Reference for Bekhorot 6:42

רב מרי מילתא הוא דעבד ואתי בה לידי תקלה:

Now, since he forbade the shearing and the working of the animals and gave them to the Priests, why did he give [a heathen] possession of the ears [of the firstlings? ]<span class="x" onmousemove="('comment',' For in this manner he carried out the prohibitions in connection with the firstling.');">²⁵</span>

Jastrow