GEN1174 Mercy is so strong a part of our tradition that a substantial body of Jewish law and practice prohibits any kind of cruelty to animals, a duty that the rabbis said was commanded by the Torah Shabbat 128b The acts forbidden because they generate tzar ba’alei hayyim, the pain of living things, have their source in the narratives as well as the legislation of the Bible. Rebecca tended to Eliezer’s camels as soon as she saw that he had slaked his thirst. This so impressed Abraham’s servant that he knew she was the right woman to be Isaac’s wife [this verse]. “R. Judah said in the name of Rav: A man may eat nothing until he has fed his animals. For the Torah the first indicates, ‘I will give grass in your fields for your cattle,’ and only later says, ‘You shall eat and be satisfied’ [Deuteronomy 11:15] Berachot 40b.   A related law prohibits a person from buying an animal unless he first has enough food to feed it adequately. Yerushalmi Yevamot 15:3 “It says something about a person’s goodness when his animals are well fed and satisfied” Sifre Deuteronomy 43.  A Talmudic tale about Judah ha-Nasi, the Patriarch of the Palestinian Jewish community in the late second century C.E. and the chief compiler of the Mishnah law code, stresses the importance of these laws. “The sufferings of Rabbi came because of an act he did that lacked compassion, and left because of an act that he did that was full of compassion. One day a calf was being taken to the slaughterhouse. It broke away and hid under Rabbi’s robe.   ‘Go,’ said Rabbi, ‘for this you were created.’ Because of this hardheartedness, sickness came upon him. Sometime later, Rabbi’s maidservant was sweeping his house when he saw that she was about to sweep away a nest full of weasel pups. ‘Let them be,’ he said to her, for it is written, ‘And God’s compassion is over all God’s works’” [Psalm 145:9] Bava Metzia 85a.  The detailed laws of the kosher slaughtering of animals, shehitah, rest upon this compassion for animals, requiring that when we kill them for food, we make sure that they die instantly and painlessly. Thus we must use a perfectly sharpened knife, one free of any nicks or rough edges Aaron, Sefer Hahinukh [The book of instruction], 451. To this day the shohet must test his knife before using it. Should he find an imperfection, he must immediately sharpen it away or set it aside and use another knife. In the same spirit, citing the negative example of the biblical hunter Esau, the rabbis prohibit killing merely for sport.  Avodah Zarah 18b. BOROJMV 75-76