Leviticus 11:4

Nevertheless these shall ye not eat of them that chew the cud, or of them that divide the hoof: as the camel, because he cheweth the cud, but divideth not the hoof; he is unclean unto you.

Cross-reference

Deuteronomy 14 is a parallel passage repeating the dietary laws, including the camel as unclean—reinforcing the same teaching.

Genesis 7:2 distinguishes clean and unclean animals for the ark, the same classification system underlying the camel's uncleanness.