Reference for Bava Kamma 85:11

איתיביה אביי המית שורי את פלוני או שורו של פלוני ה"ז משלם ע"פ עצמו מאי לאו כופר

that [on the contrary] where the debt had been collected in money the first-born would take [in it a double portion],<span class="x" onmousemove="('comment',' For the money collected is considered in the eye of the law as the money which was lent to the father of the debtor. ');">¹¹</span>

Jastrow