Compassion is a human emotion prompted by the pain of others. More vigorous than empathy, the feeling commonly gives rise to an active desire to alleviate another's suffering. It is often, though not inevitably, the key component in what manifests in the social context as altruism. In ethical terms, the various expressions down the ages of the so-called Golden Rule embody by implication the principle of compassion: Do to others what you would have them do to you. 
The English noun compassion, meaning to suffer together with, comes from the Latin. Its prefix com- comes directly from com, an archaic version of the Latin preposition and affix cum (= with); the -passion segment is derived from passus, past participle of the deponent verb patior, patī, passus sum. Compassion is thus related in origin, form and meaning to the English noun patient (= one who suffers), from patiens, present participle of the same patior, and is akin to the Greek verb πάσχειν (= paskhein, to suffer) and to its cognate noun πάθος (= pathos).
The Christian Bible's Second Epistle to the Corinthians is but one place where God is spoken of as the "Father of compassion" and the "God of all comfort" (1.3). The life of Jesus embodies for Christians the very essence of compassion and relational care. Christ's example challenges Christians to forsake their own desires and to act compassionately towards others, particularly those in need or distress. Jesus assures his listeners in the Sermon on the Mount that, "Blessed are the merciful, for they shall obtain mercy." In the Parable of the Good Samaritan he holds up to his followers the ideal of compassionate conduct.
The heritage within Western Christendom of compassion as the principle of charity has resulted in recent times in the growth of remarkable charitable phenomena such as Oxfam, Médecins sans Frontières and Live Aid with global reach and budgets of millions of dollars. True Christian compassion, say the Gospels, should extend to all, even to the extent of loving one's enemies.
In the various Hindu traditions, compassion is called DAYA, and, along with charity and self-control, is one of the three central virtues. The importance of compassion in the Hindu traditions reaches as far back as the Vedas, sacred texts composed over a period prior to 1500 B.C. While the early Vedas sometimes glorify war and the worship of the war god, Indra, Indra too is compassionate towards humans & humanity, though he is war god, he is discompassionate towards Asuras - The evil people who cause sufferings to human race, the later Vedas demonstrate a greater sensitivity to the values of compassion. The central concept particularly relevant to compassion in Hindu spirituality is that of ahimsa. The exact definition of ahimsa varies from one tradition to another. Ahimsa is a Sanskrit word which can be translated most directly as "refraining from harmfulness." It is a derivation of himsa which means harmful, or having the intent to cause harm.
The prayers of Vasudeva Datta, for example, a 16th century Vaishnava holy man or sadhu, exemplify compassion within Gaudiya Vaishnavism. He prayed to the Lord Krishna asking him to "deliver all conditioned souls" because his "heart breaks to see the sufferings of all conditioned souls".
Compassion is that which makes the heart of the good move at the pain of others. It crushes and destroys the pain of others; thus, it is called compassion. It is called compassion because it shelters and embraces the distressed. - The Buddha. Compassion or karuna is at the transcendental and experiential heart of the Buddha's teachings. He was reputedly asked by his secretary, Ananda, "Would it be true to say that the cultivation of loving kindness and compassion is a part of our practice?" To which the Buddha replied, "No. It would not be true to say that the cultivation of loving kindness and compassion is part of our practice. It would be true to say that the cultivation of loving kindness and compassion is all of our practice."
The first of what in English are called the Four Noble Truths is the truth of suffering or dukkha (unsatisfactoriness or stress). Stress is identified as one of the three distinguishing characteristics of all conditioned existence. It arises as a consequence of the failure to adapt to change or anicca (the second characteristic) and the insubstantiality, lack of fixed identity, the horrendous lack of certainty of anatta (the third characteristic) to which all this constant change in turn gives rise. Compassion made possible by observation and accurate perception is the appropriate practical response. The ultimate and earnest wish, manifest in the Buddha, both as archetype and as historical entity, is to relieve the suffering of all living beings everywhere.
The Dalai Lama has said, "If you want others to be happy, practice compassion. If you want to be happy, practice compassion." The American monk Bhikkhu Bodhi states that compassion "supplies the complement to loving-kindness: whereas loving-kindness has the characteristic of wishing for the happiness and welfare of others, compassion has the characteristic of wishing that others be free from suffering, a wish to be extended without limits to all living beings. Like metta, compassion arises by entering into the subjectivity of others, by sharing their interiority in a deep and total way. It springs up by considering that all beings, like ourselves, wish to be free from suffering, yet despite their wishes continue to be harassed by pain, fear, sorrow, and other forms of dukkha."
At the same time, it is emphasised that in order to manifest effective compassion for others it is first of all necessary to be able to experience and fully appreciate one's own suffering and to have, as a consequence, compassion for oneself. The Buddha is reported to have said, "It is possible to travel the whole world in search of one who is more worthy of compassion than oneself. No such person can be found."
Compassion for all life, human and non-human, is central to the Jain tradition. Though all life is considered sacred, human life is deemed the highest form of earthly existence. To kill any person, no matter their crime, is considered unimaginably abhorrent. It is the only substantial religious tradition that requires both monks and laity to be vegetarian. It is suggested that certain strains of the Hindu tradition became vegetarian due to strong Jain influences. The Jain tradition's stance on nonviolence, however, goes far beyond vegetarianism. Jains refuse food obtained with unnecessary cruelty. Many practice a lifestyle similar to veganism in response to factory farming. Jains run animal shelters all over India: Delhi has a bird hospital run by Jains; every city and town in Bundelkhand has animal shelters run by Jains. Jain monks go to inordinate lengths to avoid killing any living creature, sweeping the ground in front of them in order to avoid killing insects, and even wearing a face mask to avoid inhaling the smallest fly.
In the Jewish tradition, God is the Compassionate and is invoked as the Father of Compassion: hence Raḥmana or Compassionate becomes the usual designation for His revealed word. (Compare, below, the frequent use of raḥman in the Quran). Sorrow and pity for one in distress, creating a desire to relieve, is a feeling ascribed alike to man and God: in Biblical Hebrew, ("riḥam," from "reḥem," the mother, womb), "to pity" or "to show mercy" in view of the sufferer's helplessness, hence also "to forgive" (Hab. iii. 2); , "to forbear" (Ex. ii. 6; I Sam. xv. 3; Jer. xv. 15, xxi. 7.) The Rabbis speak of the "thirteen attributes of compassion." The Biblical conception of compassion is the feeling of the parent for the child. Hence the prophet's appeal in confirmation of his trust in God invokes the feeling of a mother for her offspring (Isa. xlix. 15). 
Lack of compassion, by contrast, marks a people as cruel (Jer. vi. 23). The repeated injunctions of the Law and the Prophets that the widow, the orphan and the stranger should be protected show how deeply, it is argued, the feeling of compassion was rooted in the hearts of the righteous in ancient Israel. Compassion, empathy, altruism, kindness and love are frequently used interchangeably in common usage. When the concept is examined in depth it becomes clear that compassion is more than simply a human emotion. Kabbalah, the Jewish mystical tradition, is particularly clear about this. One rabbi has put it this way:
|“||Kindness gives to another. Compassion knows no other.||”|
 This idea is greatly expanded by Michael Laitman who says, "Thus if we thoroughly examine Nature's elements, we will see that altruism is the basis of life." Here altruism is the word used but the concept is consistent with an understanding of compassion 
A classic articulation of the Golden Rule (see above) came from the first century Rabbi Hillel the Elder. Renowned in the Jewish tradition as a sage and a scholar, he is associated with the development of the Mishnah and the Talmud and, as such, one of the most important figures in Jewish history. Asked for a summary of the Jewish religion in the "while standing on one leg" meaning in the most concise terms, Hillel stated: "That which is hateful to you, do not do to your fellow. That is the whole Torah. The rest is the explanation; go and learn."  Post 9/11, the words of Rabbi Hillel are frequently quoted in public lectures and interviews around the world by the prominent writer on comparative religion Karen Armstrong.
In the Muslim tradition, foremost among God's attributes are mercy and compassion or, in the canonical language of Arabic, Rahman and Rahim. Each of the 114 chapters of the Quran, with one exception, begins with the verse, "In the name of God the Merciful, the Compassionate". The Arabic word for compassion is rahmah. As a cultural influence, its roots abound in the Quran. A good Muslim is to commence each day, each prayer and each significant action by invoking God the Merciful and Compassionate, i.e. by reciting Bism-i-llah a-Rahman-i-Rahim.
The Muslim scriptures urge compassion towards captives as well as to widows, orphans and the poor.Zakat, a toll tax to help the poor and needy, is obligatory upon all Muslims (9:60). One of the practical purposes of fasting or sawm during the month of Ramadan is to help one empathize with the hunger pangs of those less fortunate, to enhance sensitivity to the suffering of others and develop compassion for the poor and destitute. The Prophet is referred to by the Quran as the Mercy of the World (21:107); and one of the sayings of the Prophet informs the faithful that, "God is more loving and kinder than a mother to her dear child." 
Compassion is the human feeling of pity over another's sorrows, along with the desire to help others in their situations.
Sorrow and pity for one in distress, creating a desire to relieve, a feeling ascribed alike to man and God; in Biblical Hebrew, (hebrew) ("riḥam," from "reḥem," the mother, womb), "to pity" or "to show mercy" in view of the sufferer's helplessness, hence also "to forgive" (Hab 3:2); (hebrew) , "to forbear" (Ex 2:6; 1Sam 15:3; Jer 15:15, Jer 21:7); (hebrew) "to spare" (Deut 7:16, Deut 13:8; Ezek 7:4, Ezek 20:17); (hebrew) and (hebrew) , "to be gracious" and "kind" (Isa 22:23 [if the text is correct]; Prov 20:28; Job 6:14; Num 14:19; Gen. xxx. ii. 10; Isa. lxiii. 7). The Rabbis speak of the "thirteen attributes of compassion," (hebrew) (Ex 34:6; Pesiḳ. 57a; R. H. 17a). Later a distinction is made between attributes of compassion and those of love ( (image) ; see Asher Ben David in his commentary on the Thirteen Attributes, where he classifies them under "justice," "love," and "compassion").
The Biblical conception of compassion is the feeling of the parent for the child ("pitieth"; Ps. ciii. 13). Hence the prophet's appeal in confirmation of his trust in God figures the feeling of a mother for her offspring (Isa. xlix. 15), and Pharaoh's daughter, moved by maternal sympathy, has compassion on the weeping babe (Ex. ii. 6).
But this feeling should mark the conduct of man to man (I Sam. xxiii. 21); its possession is a proof that men are among those deserving recognition as "blessed unto Yhwh"; and in Zech. vii. 9 it is included among the postulates of brotherly dealings. Inversely, the lack of compassion mark..s a people as "cruel" ( (image) ; Jer. vi. 23). The Chaldeans are without compassion in that they slay the young and helpless (II Chron. xxxvi. 17); and Edom is censured for having cast away all "pity" (Amos i. 11).The poor are especially entitled to compassion (A. V. "pity"; Prov. xix. 17). The repeated injunctions of the Law and the Prophets that the "widow," the "orphan," and the "stranger" shall be protected show how deeply rooted was the feeling of compassion in the hearts of the righteous in Israel. It can not be admitted that the provisions for the extermination of the seven original Palestinian tribes (Deut. vii. 3, 16) indicate the absence of kindly sympathy for aliens. Even if these provisions do not, as the critical school insists, represent merely pious wishes, they are at least entitled to be regarded as war measures, and, as such, were exceptional. They rank with similar provisions to cover the cases of the murderer and the false prophet (Deut. xiii. 8; xix. 13, 21). The very horror with which the conduct of the Chaldees and Edom (see above) was regarded proves the contrary. Even the "enemy" was within the sweep of Jewish compassion. And so was the dumb animal, as the humane provisions of the Pentateuch against cruelty to them demonstrate (see Cruelty to Animals).
The physiological psychology of the Bible places the seat of the sympathetic emotions in the bowels. But the eyes were credited with the function of indicating them. Hence the frequent use of the expression "the eye has," or "has not," pity. The "length of the breath"—that is, in anger or wrath ( (image) )—is another idiomatic expression for compassionate forbearance.
God is full of compassion (Ps. ciii. 11, cxlv. 3); and this compassion is invoked on men (Deut. xiii. 17), and promised to them (Deut. xxx. 3). "His compassions fail not, being new every morning" (Lam. iii. 22). Repeatedly He showed His compassion (II Kings xiii. 23; II Chron. xxxvi. 15). His "mercy [or "compassion"] endureth forever." He loveth the "poor," the "widow," the "orphan," and the "stranger." He is named (image) ("gracious and full of compassion"; Ex. xxxiv. 6, passim). To obtain His "compassion," as the quality that pardons, sinners must first repent and return to Him (II Chron. xxx.). But when they do this, even non-Jews will experience His compassion (Book of Jonah). For God "pitieth" like a father those "that fear him" (Ps. ciii. 13).
These Biblical ideas become the foundation of the ethical and theological teachings of the Rabbis. Israel especially should be distinguished for its compassionate disposition (Yeb. 79a), so that one who is merciful falls under the presumption of being of the seed of Abraham (Beẓ. 32b). One who is not prone to pity and forbearance is cruel (B. Ḳ. 92a), and this though to be compassionate has the tendency to rob life of its savor (Pes. 113b). The thoughtlessly frivolous is like a cruel man, but one who is compassionate experiences the lot of the poor man (B. B. 145b). Compassion shown to fellow man will win compassion from on high (Shab. 151a). Eyes without pity will become blind, and hands that will not spare will be cut off (Ta'an. 21a). Women are recognized as prone to pity (Meg. 14b). In fact, this trait of its women was one of the glories of Jerusalem (B. B. 104b). To praise God meant to become merciful like unto Him (Shab. 133b; Ex. xv.). Strangers certainly came within the scope of the rabbinical ideas of compassion. Their dead were buried with the dead of Israel; their poor were assisted; their sick were visited (Giṭ. 61a, Tos. v. 4, 5). The angels when about to celebrate in song Israel's victory over Egypt were hushed by God with the rebuke: "The works of My hands have been drowned, and you would intone jubilant pæans!" (Meg. 10b).
The peculiar interdiction of the explanation of Pentateuchal laws as manifestations of divine compassion for dumb creatures (Ber. 33b) proves that this explanation was popular (see Cruelty to Animals). But the Rabbis often lay stress on the fact that the Torah takes great care to "spare" ( (image) ) the property of man (Soṭah 14b; Nega'im xii.).
God is recognized as the "Compassionate" ( (image) ; compare the frequent use of "raḥman" in the Koran). He is invoked as the (image) (Father of Compassion). So close is this association with Him that "Raḥmana" becomes the usual designation for His revealed word. He suffers with His people (Rabbi Meïr: "The Shekinah exclaims with the suffering patient, 'Oh, my head! Oh, my arm!'" Sanh. iv. 46a; but see Levy, s.v. (image) ). He mourns with His people (Lam. R. to i. 1). The relation which God's "compassion" sustains to His "justice" is also a subject of rabbinical inquiry, as it was among the early Christian sects. When the shofar is sounded "God's quality of compassion mounts the throne" (Pesiḳ. 151b, 155a; Lev. R. xxix.; compare also Abraham's prayer [Yer. Ta'an. 65d]). The name "Elohim" designates God's justice ( (image) ), and the name Yhwh God's compassion ( (image) ; Ex. R. vi.). Even while God is preparing to inflict punishment, God's compassion is bestirring itself (Yer. Ta'an. 65b, bottom; Pesiḳ 161b; Midr. Teh. to Ps. 86; Pes. 87b). Philo says "God's pity is older than His judgment" ("Quod Deus Sit Immutabilis," 16). The name Yhwh is repeated twice in Ex. xxxiv. 6 to allay the fears of Moses. As before the sin of the golden calf had been committed God dealt with Israel according to His compassion, so even now, after their sinning, will He deal with them in mercy (Pesiḳ. R. 5; Num. R. xii.).