Numbers 18:15

Beast. The Rabbins restrain this to the ass alone, which they pretend was deemed the only unclean animal by the Israelites, in Egypt, when this law was established; and Moses indeed specifies it alone, Exodus xiii. 13. (Abenezra) --- But we cannot doubt but that camels, and all other unclean animals, were to be included, if the Hebrews kept them; (Calmet) and those which were rendered impure by some defect, were also to be redeemed. (Menochius)