Mishneh Torah — Positive Mitzvot מצוות עשה, Chapter 149
The full Hebrew text of Mishneh Torah, Positive Mitzvot, Chapter 149, with English translation by Maimonides (Rambam).
לבדוק בסימני בהמה, שנאמר: "זאת החיה אשר תאכלו" (ויקרא יא,ב).
To check the signs [with which] animals [are identified], as kosher, as [Leviticus 11:2] states: "These are the animals which you may eat...."