Leviticus 11:2
Speak unto the children of Israel, saying, These are the beasts which ye shall eat among all the beasts that are on the earth. Speak unto the children of Israel, saying, These are the beasts which ye shall eat among all the beasts that are on the earth.
The verse opens God's instructions to Israel through Moses distinguishing which beasts may be eaten from those pronounced unclean. It belongs to the strict training given in the wilderness before entering Canaan, including health principles and sanitary laws. Animal food was permitted only within careful limits, with many animals, birds, and fish declared unclean. Animals permitted for food had to be in good condition, animals torn by beasts or that died on their own could not be eaten, and blood had to be carefully drained.
Swine and certain other animals were excluded because their flesh was likely to pollute the blood and shorten life. Swine's flesh was prohibited because it is hurtful, filling the system with humors and in that warm climate often producing leprosy, with effects more injurious there than in a colder climate; swine were never designed to be eaten under any circumstances but to be scavengers devouring decaying substances to preserve health. Other animals were also forbidden because they were not the best articles of food, with God specifying those considered least objectionable for food. The prohibition of unclean beasts was given to protect health and preserve life, not to impose arbitrary authority, helping keep the blood pure and the mental and physical faculties sound.
Submission to these wise prohibitions would have removed what injures health and left no sickness among Israel, while lusting for forbidden food brought disease. Eating what the law forbade would defile the Hebrews, who were expressly forbidden to eat it. These restrictions limited the harms of a flesh diet, which Israel had sought despite the better food God had provided. Daniel and his companions refused such meats because they believed this food would impair their health and clear thinking, which they needed to serve God and represent their faith, practicing temperance and treating obedience to God as the highest rule of life. The directions were later distorted by going beyond them with extreme rules and ceremonies, such as requiring people to strain all drinking water to remove even the smallest insect, burdening people with constant scrutiny of what was clean or unclean.