פירוש על קידושין 35:8

A Jew may be sold to recover the value of an item he stole. But if he cannot afford to pay the double payment owed by a thief, he is not sold for the double payment. If a Jew falsely testifies that another person stole, then the false witness must pay back the amount he accused the other of stealing. But if he cannot afford this payment, he is not sold to recover it. And if he was sold once, and then went free, he cannot be sold again.