Leviticus 11:37

People probably moistened grain with water to cook it for food. Eating contaminated grain was like eating a dead animal. But if they planted the grain, the new plant and its grain were ceremonially clean.

Dead animals could make objects and people ceremonially unclean. Even a ceremonially clean animal that died without its blood drained was unclean (Leviticus 11:39–40). If a person touched the body of a dead animal, they were unclean until evening. Household items that touched the body of a dead animal needed purification or the people had to destroy the items (11:25, 28, 32, 40; 11:33, 35).

These chapters explain the rules about purity. Mixing different types of animals was forbidden (see Deuteronomy 22:9–11). This is because it opposed God's natural order. Creatures like fish without fins and scales, meat-eating animals, crawling insects, and animals without split hooves were considered "abnormal." They crossed the boundaries between "normal" types and were not suitable for food or offerings (see also Deuteronomy 14:1–21). The dietary laws intended to set Israel apart as a holy people from other nations (Leviticus 11:44–45).