He prohibited us from eating impure birds. And that is His, may He be exalted, saying about those species, "These you shall consider repulsive from among the birds; they may not be eaten, etc." (Leviticus 11:13). And one who eats a kazayit of their meat is lashed. And the regulations of this commandment - along with the two before it - have already been explained in the third [chapter] of Chullin. (See Parashat Shemini; Mishneh Torah, Forbidden Foods 2.)