הלכה אויף דברים 14:6

The identification marks of cattle and game are indicated in the Torah, and there are two of them: "cloven hooves and ruminants" (Lev. 11:3; Deut. 14:6). All ruminants are missing their upper incisors. All ruminants have split hooves, except the camel. And all animals that have cloven hoofs are ruminants, except the hog.

From the scripture (Deut. 14:6): "and every beast that parts the hoof, forming thereby two entirely cloven hoofs, and ruminant [among the beasts, that may you eat.]" — I derive that everything that is not cloven-hoofed and ruminant must be forbidden. A prohibition derived from a commandment becomes a commandment. Regarding the camel, hare, and hyrax it says (Lev. 11:4; Deut. 14:7): "These you shall not eat among ruminants" — you see that they are forbidden even though they have one sign, certainly other non-kosher cattle or game that has none of the signs. The injunction against eating them is in addition to that derived commandment.