Reference for Menachot 216:3

שני שוורין אלו עולה ונסתאבו רצה יביא בדמיהן אחד ורבי אוסר: מאי טעמא

- Because it is like the case where he vowed a large animal and he brought a small one.<span class="x" onmousemove="('comment',' For generally speaking two oxen, even though together only equal in price to one, are more profitable than one.');">³</span> For even though they have suffered a blemish.<span class="x" onmousemove="('comment',' So that the obligation of this man's vow has come to an end.');">⁴</span>

Jastrow

Jastrow