Leviticus 25:39
TSK
"'If your brother has grown poor among you, and sells himself to you; you shall not make him to serve as a slave.
TSK
Treasury of Scripture Knowledge references in WEB.
"'If your brother has grown poor among you, and sells himself to you; you shall not make him to serve as a slave.
For, behold, I begin to work evil at the city which is called by my name; and should you be utterly unpunished? You shall not be unpunished; for I will call for a sword on all the inhabitants of the earth, says Yahweh of Armies.
Therefore "If your enemy is hungry, feed him. If he is thirsty, give him a drink; for in doing so, you will heap coals of fire on his head."