Leviticus 11:29-38

These verses deal with swarming creatures and the pollution they create. Swarming may have been regarded as an unnatural, chaotic means of locomotion. The norm would have been orderly progress. Anything on which a swarming insect fell became polluted (unclean, Leviticus 11:32). Those objects that water would cleanse could be reused, but those that water would not cleanse could not. However if one of these creatures fell into a spring or cistern, an exception was made. Neither the container nor the water became impure, only the person who fished the dead animal out would be. God may have granted this exception since declaring water supplies and large containers unclean would have had drastic consequences in the arid regions where the Israelites lived. There was also apparently a distinction between seed for sowing and seed for eating (Leviticus 11:37-38).