כָּל־צִפּ֥וֹר טְהֹרָ֖ה תֹּאכֵֽלוּ׃
무릇 정한 새는 너희가 먹으려니와
Sifrei Devarim
Abba Channan says in the name of R. Eliezer: The shesuah is a beast in itself; it has two backs and two spines.
Sifrei Devarim
(Devarim 14:11) "Every clean bird you may eat": Because it is written (Vayikra 14:4) "And the Cohein shall command, and he shall take for the one to be cleansed (from leprosy) two birds," I might think that just as the slaughtered bird is forbidden (to be eaten), so, the sent-away bird; it is, therefore, written "Every clean bird you may eat (including the sent-away bird).