Deuteronomy 24:18
But thou shalt remember that thou wast a bondman in Egypt, and the LORD thy God redeemed thee thence: therefore I command thee to do this thing. But thou shalt remember that thou wast a bondman in Egypt, and the LORD thy God redeemed thee thence: therefore I command thee to do this thing.
The command rests on remembering having been a bondman in Egypt and the Lord God redeeming His people from there. That deliverance places the redeemed under special obligation to treat the stranger, the fatherless, and the widow justly and kindly and never to pervert their judgment. Provision for the needy belongs to the command, by leaving the forgotten sheaf, the remaining olives, and the ungleaned grapes for the stranger, the fatherless, and the widow rather than withholding the gleanings of harvest, olives, and grapes.
The command also forbids oppressing the poor and needy hired servant by requiring prompt payment of his hire, and forbids taking a widow's clothing in pledge, with the result that God will bless the work of their hands. For those serving God this means strict integrity in all details of business life, including fair prices, honest dealing without overreaching, refusing to take advantage of a neighbor's need, frankly disclosing defects, and relieving a less fortunate brother's necessities.