Thou shalt neither vex a stranger, nor oppress him: for ye were strangers in the land of Egypt.

Wesley's Notes

22:21 A stranger must not be abused, not wronged in judgment by the magistrates, not imposed upon in contracts, nor any advantage taken of his ignorance or necessity, no, nor must he be taunted, or upbraided with his being a stranger; for all these were vexations. For ye were strangers in Egypt - And knew what it was to be vexed and oppressed there. Those that have themselves been in poverty and distress, if Providence enrich and enlarge them, ought to shew a particular tenderness towards those that are now in such circumstances as they were in formerly, now doing to them as they then wished to be done by.

Matthew Henry's Concise Commentary

22; 1 - 31 Judicial laws. - The people of God should ever be ready to show mildness and mercy, according to the spirit of these laws. We must answer to God, not only for what we do maliciously, but for what we do heedlessly. Therefore, when we have done harm to our neighbour, we should make restitution, though not compelled by law. Let these scriptures lead our souls to remember, that if the grace of God has indeed appeared to us, then it has taught us, and enabled us so to conduct ourselves by its holy power, that denying ungodliness and wordly lusts, we should live soberly, righteously, and godly in this present world, Titus 2:12. And the grace of God teaches us, that as the Lord is our portion, there is enough in him to satisfy all the desires of our souls.