John Calvin Commentary Deuteronomy 23:7

"Thou shalt not abhor an Edomite; for he is thy brother: thou shalt not abhor an Egyptian, because thou wast a sojourner in his land." — Deuteronomy 23:7 (ASV)

You shall not abhor an Edomite. So that the punishment pronounced against the Moabites and Ammonites would be more strongly emphasized, He commands the Edomites and Egyptians to be admitted in the third generation. The Edomites were to be admitted because they derived their origin from the same ancestor, Isaac, as they were the descendants of Esau; the Egyptians, because they had once been hosts to Israel. For from this it was clear that the Ammonites and Moabites had been dishonored because of their guilt, when not even foreigners were treated this way.

Now, although Esau had cut himself off from the privilege of believers, the door was again opened to his children, provided they returned to their source and origin and, in the humility of faith, admitted the primogeniture of Jacob, who had been chosen when their father was bypassed or degraded.

But what is meant by this inequality of punishment, when the crime was identical? For Edom appeared in arms against Israel before Moab did, and compelled them to travel by another route. Edom did not fight with hired curses for Israel’s destruction. However, since Edom, when humbly pleaded with on the basis of their old relationship, had not only refused them passage but had also advanced against them with a large army, it should have been treated with no less severity than Amalek or Ammon. Besides, being connected to them by a closer tie of blood, the Edomites were less excusable in their hostility.

I find, then, no reason why God showed greater clemency to them than to the others whom He treated more severely, except that He wished to show that it depends on His own will to chastise some more lightly for the same sins for which He takes more severe vengeance on others. And, since all are deserving of utter destruction, He justly retains in His own hand the free right to spare whomever He wills. We must here adore His judgments, into the depths of which we cannot penetrate. Nor is this inequality a basis for the noisy objections of the ungodly, as if He were inconsistent with Himself and acted contrary to the rules of His Law. For in doing so, He does not judge in different ways; rather, condemning all alike, He shows favor to whomever He pleases, or lessens a part of their punishment.

A question may also arise concerning the Egyptians: why God places His people under an obligation to them because they had lived as foreigners in their land. For it was barbarous and inhospitable cruelty for them to oppress the wretched fugitives who had trusted in their good faith. But God here refers to their initial reception, as in Isaiah 52:4. In that passage, comparing the Egyptians with the Assyrians, He says that the latter oppressed Israel like robbers, while the former had ruled over them not without a reason, because the people had gone down there of their own accord. Although, therefore, the Israelites had been unjustly oppressed by their fierce tyranny, God still wished for their past kindness to be acknowledged. This was because Israel's scarcity and famine had been relieved, and the refugees were kindly received when the inhabitants of Canaan were dying of hunger.