2 Kings 4:1

The creditor is come ... - The Law of Moses, like the Athenian and the Roman law, recognized servitude for debt, and allowed that pledging of the debtor’s person, which, in a rude state of society, is regarded as the safest and the most natural security (see the marginal reference). In the present case it would seem that, so long as the debtor lived, the creditor had not enforced his right over his sons, but now on his death he claimed their services, to which he was by law entitled.