Calvin's treatment of Leviticus 19:33-34 on the treatment of strangers comes under his handling of the 8th Commandment. Calvin's insinuation is that these are case laws to theft. By depriving those who have no human protection we in effect wrong them.

21 And a sojourner shalt thou not wrong, neither shalt thou oppress him: for ye were sojourners in the land of Egypt. 22 Ye shall not afflict any widow, or fatherless child. 23 If thou afflict them at all, and they cry at all unto me, I will surely hear their cry; 24 and my wrath shall wax hot, and I will kill you with the sword; and your wives shall be widows, and your children fatherless. — Exodus 22:21-24

33 And if a stranger sojourn with thee in your land, ye shall not do him wrong. 34 The stranger that sojourneth with you shall be unto you as the home-born among you, and thou shalt love him as thyself; for ye were sojourners in the land of Egypt: I am Jehovah your God. — Leviticus 19:33-34

"Before I pass on to the other iniquities, I have thought fit to introduce this precept, wherein the people are commanded to cultivate equity towards all without exception. For if no mention had been made of strangers, the Israelites would have thought that, provided they had not injured any one of their own nation, they had fully discharged their duty; but, when God recommends guests and sojourners to them, just as if they had been their own kindred, they thence understand that equity is to be cultivated constantly and towards all men.

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Moreover, it must be observed that, in the second passage, they are commanded to love strangers and foreigners as themselves. Hence it appears that the name of neighbor is not confined to our kindred, or such other persons with whom we are nearly connected, but extends to the whole human race; as Christ shows in the person of the Samaritan, who had compassion on an unknown man, and performed towards him the duties of humanity neglected by a Jew, and even a Levite. (Luke 10:30.)" — Harmony of the Gospel