Midrash for Bava Metzia 61:16

א"ל שלח אפי' מאה פעמים משמע תשלח אין לי אלא לדבר הרשות לדבר מצוה מנין ת"ל תשלח מ"מ

And when he teaches that if it is running among the vineyards there is a case of loss, implying that if it is feeding among the vineyard there is none, the reference is to the loss of itself;<span class="x" onmousemove="('comment',' I.e., of the animal. ');">¹³</span>

Sifrei Devarim

Sifrei Devarim