(3.) ‏כלאים‎.—Mixture of different kinds. “Thou shalt not sow thy field with two kinds of seed” (Lev. xix. 19). [170] “Thou shalt not sow thy vineyard with two kinds of seed” (Deut. xxii. 9). In the former case only the sowing of divers kinds is prohibited, but the produce of such sowing is not forbidden; in the latter case, if the law is transgressed, the produce of both the vine and the seed is not to be used for any purpose whatever (‏אסור בהנאה‎), for the law is followed by the words, “lest the whole fruit be forfeited, the seed which thou hast sown and the increase of the vineyard.” Although these and similar [171] precepts are introduced by the words “Ye shall keep my statutes (‏חקתי‎),” and no reason is given for the enactment of these statutes, it seems, from the position occupied by these laws in a section of moral precepts, that they serve as reminders of the important lesson that our conduct should be regulated by the principles of contentment and simplicity of life, principles which are the best safeguard against undue desire for luxury and superfluity. The prohibition of sowing divers kinds of seed further reminds us of the importance of preserving our heart in a state of simplicity and purity; that twofold weights, twofold measures, and especially a twofold heart are an abomination to the Lord. In reference to animal food the following principles are observed:— 1. The killing of animals and the consuming of their flesh must not tend to create savage and cruel habits. It is therefore forbidden— (a.) To cut off a piece of flesh from a living animal for our food (‏אבר מן החי‎ “a limb of a living animal”). (b.) To kill the parent with its young on the same day (Lev. xxii. 28; comp. Deut. xxii. 6). (c.) To give unnecessary pain to the animal in killing it. The various regulations for the lawful killing of animals, ‏שחיטה‎, handed down by Tradition as Mosaic, ‏הלכה למשה מסיני‎, are not only in harmony with this principle, but seem in many instances to have been dictated by it. (d.) To eat the blood of beasts and birds (Lev. xvii. 12, 14). The blood contained in the meat is removed as far as possible by having the meat soaked in water for half-an-hour, and then kept covered with salt for an hour, the salt being again removed by rinsing. This process is called kasher; that is, preparing the meat so as to make it kasher (‏כשר‎ “fit for food”). 2. The flesh of beasts and birds that have died from any other cause than having been killed in the manner prescribed is forbidden. The flesh of animals that have been killed in the prescribed manner, but are found to have been affected with some dangerous disease, is also forbidden as t’refah (‏טרפה‎). [172] 3. With regard to the distinction between animals allowed for food and those forbidden, all animals are divided into ‏בהמה‎ and ‏חיה‎ “cattle and beast,” ‏וף‎ “bird,” ‏דג‎ “fish,” and ‏שרץ‎ “creeping thing.”