Verse 31. - And he said, Behold now, I have taken upon me (vide Ver. 27) to speak unto the Lord (Adonai): Peradventure there shall be twenty found there. And he said, I will not destroy it for twenty's sake.

18:23-33 Here is the first solemn prayer upon record in the Bible; and it is a prayer for the sparing of Sodom. Abraham prayed earnestly that Sodom might be spared, if but a few righteous persons should be found in it. Come and learn from Abraham what compassion we should feel for sinners, and how earnestly we should pray for them. We see here that the effectual, fervent prayer of a righteous man avails much. Abraham, indeed, failed in his request for the whole place, but Lot was miraculously delivered. Be encouraged then to expect, by earnest prayer, the blessing of God upon your families, your friends, your neighbourhood. To this end you must not only pray, but you must live like Abraham. He knew the Judge of all the earth would do right. He does not plead that the wicked may be spared for their own sake, or because it would be severe to destroy them, but for the sake of the righteous who might be found among them. And righteousness only can be made a plea before God. How then did Christ make intercession for transgressors? Not by blaming the Divine law, nor by alleging aught in extenuation or excuse of human guilt; but by pleading HIS OWN obedience unto death.And he said, behold now, I have taken upon me to speak unto the Lord,.... See Gill on Genesis 18:27,

Peradventure there shall be twenty found there; wouldest thou destroy it, such a number being in it; or, wouldest thou spare it for their sakes?

and he said, I will not destroy it for twenty's sake; if there were no more in it, I would spare it for their sake.