Exodus 23:9
"Also thou shalt not oppress a stranger: for ye know the heart of a stranger, seeing ye were strangers in the land of Egypt."
Cross References (ranked by relevance)
Thou shalt neither vex a stranger, nor oppress him: for ye were strangers in the land of Egypt.
Cursed be he that perverteth the judgment of the stranger, fatherless, and widow. And all the people shall say, Amen.
Shouldest not thou also have had compassion on thy fellowservant, even as I had pity on thee?
In thee have they set light by father and mother: in the midst of thee have they dealt by oppression with the stranger: in thee have they vexed the fatherless and the widow.
They slay the widow and the stranger, and murder the fatherless.
Notwithstanding, if he continue a day or two, he shall not be punished: for he is his money.
Love ye therefore the stranger: for ye were strangers in the land of Egypt.