John Calvin Commentary Genesis 18:23

"And Abraham drew near, and said, Wilt thou consume the righteous with the wicked?" — Genesis 18:23 (ASV)

Will you also destroy the righteous with the wicked? It is certain that when God chastises the body of a people, He often involves the good and the reprobate in the same punishment. So Daniel, Ezekiel, Ezra, and others like them, who worshipped God in purity in their own country, were suddenly hurried away into exile, as by a violent tempest, even though it had been said

The land vomiteth out her inhabitants, because of their iniquities (Leviticus 18:25).

But when God thus seems to be angry with all in common, it is fitting for us to fix our eyes on the end, which will evidently distinguish the one from the other. For if the farmer knows how to separate the grains of wheat in his barn, which with the chaff are trodden under the feet of oxen or are struck out with the flail, much better does God know how to gather together His faithful people—when He has chastised them for a time—from among the wicked (who are like worthless refuse), so that they may not perish together. Indeed, by the very event, He will eventually prove that He would not permit those whom He was healing by His chastisements to perish.

For, so far is He from hastening to destroy His people when He subjects them to temporal punishments, that He is rather administering to them a medicine which will procure their salvation. I do not doubt, however, that God had denounced the final destruction of Sodom; and in this sense Abraham now takes exception, that it was by no means consistent that the same ruin should fall alike on the righteous and the ungodly.

There will, however, be no absurdity in saying that Abraham, having good hope of the repentance of the wicked, asked God to spare them, because it often happens that God, out of regard for a few, deals gently with a whole people. For we know that public punishments are mitigated because the Lord looks upon His own with a gracious and paternal eye.

In the same sense, the answer of God Himself ought to be understood: If in the midst of Sodom I find fifty righteous, I will spare the whole place for their sake. Yet God does not here bind Himself by a perpetual rule that would prevent Him, whenever He sees fit, from bringing the wicked and the just together to punishment.

And, in order to show that He has free power of judging, He does not always adhere to the same consistent moderation in this respect. He who would have spared Sodom on account of ten righteous persons refused to grant the same terms of pardon to Jerusalem (Matthew 11:24). Let us understand, therefore, that God does not here place Himself under any necessity, but He speaks thus in order to make it better known that He does not, on slight grounds, proceed to the destruction of a city of which no portion remained unpolluted.