Biblical laws dealing with the cases discussed in Bava Kamma are contained in the following passages: , and . The principle that underlies the legislation in this respect is expressed by the sentence, "He that kindled the fire shall surely make restitution".
Bava Kamma consists of ten chapters, which may be grouped as follows: damage caused without criminality (chaps. i-vi); damage caused by a criminal act (chaps. vii-x).
Two types of damages are dealt with: (1) damage caused by agents in their normal condition; (2) damage caused by agents in their abnormal condition. An instance of the first class of agents is an ox treading upon things that are in his way and thus damaging them, or eating things that are in his path. An instance of the second class is the case of a Goring Ox, as under normal circumstances an ox does not gore.
The law concerning the compensation in these cases is expressed in the Mishnah (i. 1) thus: "These four agents have in common the circumstance that they usually cause damage; that the owner has the duty to prevent the damage; and that if he fails to do so, on damage being done he must pay full compensation, with the best of his property" (compare [A. V. 5]). Before, however, giving the detailed regulations for these four kinds of damage, the Mishnah proceeds to the discussion of the second class of damages, those caused by agents in an abnormal condition.
The law of mu'ad applies to the four kinds of damage done by animals or agents in their normal condition. In addition to these the Mishnah (i. 4) enumerates the following: man, and wild beasts owned by a man—such as the wolf, the lion, the bear, and the leopard; also the serpent. Of man it is said, "Man is always fully responsible (mu'ad), whether he cause damage intentionally or unintentionally, whether awake or asleep" (ii. 6). This rule is illustrated by various instances given in the third chapter (1-7).
(1) "If a man steal an ox or a lamb and slaughter the same or sell it, five cattle shall he pay for the ox and four sheep for the lamb" (). The regulations as to how to apply this law under various circumstances are contained in chapter vii. 1-6.
(2) The compensation for injuries as the result of violence is discussed in chapter viii. Such compensation includes five items: for the permanent loss ("nezeḳ"), if any, in earning capacity; loss of time ("shebet"); pain ("ẓa'ar"); cost of the cure ("rippuy"); and insult ("boshet"). The scale of compensation for an insult, as given in the Mishnah, seems to indicate the maximum compensation, for the Mishnah adds, "The principle is that the amount depends on the injured man's station in life." Rabbi Akiba, however, opposed this principle, and desired to have one measure for all. A practical case decided by Rabbi Akiba is then cited (viii. 7). In addition to all the compensation paid, the offender must beg the injured man's pardon.
(3) He who has robbed his neighbor, and desires to make restitution, pays the full value of the thing taken and a fine of one-fifth of its value. ([A. V. vi. 2-5]). If the things taken by robbery have undergone a change, he pays according to the value the things had at the time of the robbery (ch. ix.). The last chapter considers cases in which the things taken are no longer in the hands of the robber, and concludes with the warning not to buy things suspected to be stolen. With the exception of chap. vii. 7 (on certain restrictions with regard to the rearing of cattle or poultry in Palestine), there are neither halakic nor haggadic digressions in this tractate.
The following are a few of the principles enunciated in the Gemara: According to Symmachus (Sumkus, not to be confused with Symmachus the Ebionite): Property concerning which there is a doubt whether it belongs to A or to B, is divided between A and B without either being compelled to confirm his claim by oath. The sages (chachamim) hold that he who claims what is in the possession of another, must prove his claim (hamotzi machavaro aluv haria)(B. Ḳ. 46a). A person attacked on his own grounds may take the law into his own hands, when the delay caused by going to a proper court of law would involve great loss. Whenever the whole value of the damaged object is paid, the payment is considered as compensation ("mamona"); when only half the value or a certain fixed amount is paid, the payment is considered a fine ("kenasa") (B. Ḳ. 15b). The judges in Babylonia had no right to impose a fine for any offense; the case had to be tried by qualified judges in Palestine.
The following incident will illustrate the last two rules: A man was charged before Rab Ḥisdai (in Babylonia) with having struck a fellow man with his spade. Rab Ḥisdai asked Rab Naḥman how much the offender had to pay. The latter replied that no fine could be imposed in the Babylonian courts, but that he desired to know the facts of the case. He ascertained that A and B had together a well, each of them with the right of drawing water on certain fixed days alone. Contrary to the agreement A drew water on a day that was not his. B noticed it and drove him away with his spade. Rab Naḥman's verdict was that B might with impunity have hit A a hundred times with the spade, as any delay would have involved a great loss to B (B. Ḳ. 27b). It is noteworthy that two codes of law are mentioned: the legal one ("dine adam," literally, judgments of man) and the moral one ("dine shamayim," literally, judgments of heaven). In some cases the former absolves man of an obligation, and the latter does not (Mish. vi. 4; Gem. 29a, 56a, and passim).
Some noteworthy explanations of Biblical texts may be added. The words "ḳa'asher yeba'er hagalal" (I Kings xiv. 10) are quoted as meaning (Babli 3a; see Rashi, ad loc.) "as the tooth destroyeth" (A. V. "as a man sweepeth the dung"). "Erek appayim" ("slow to anger," Ex. xxxiv. 6) is interpreted "long-suffering to both the righteous and the wicked" (ib. 50b), on account of the dual form. A Biblical verse is quoted according to its sense and not literally, as, for example (ib. 81b; compare B. M. 76a), "mihyot ṭob al tiḳḳare ra'" (when thou art kind, thou shalt not be called bad); then the question is raised, "Is it written so?" and the verse Prov. iii. 27 is cited.