Reference for Bekhorot 4:63

וחכמים אומרים

If again an Israelite gi an animal [to a heathen] to look after, although [he knows that] this is not permitted, we fine him even up to ten times its value and he gives its whole value to the Priest.<span class="x" onmousemove="('comment',' Supra 2b.');">³⁸</span>

Jastrow