Genesis 18:30 - Joseph Benson’s Commentary on the Old and New Testaments

O let not the Lord be angry The importunity which believers use in their addresses to God is such, that if they were dealing with a man like themselves, they could not but fear that he would be angry with them. But he with whom we have to do is God and not man, and he is pleased when he is wrestled with. But why then did Abraham leave off asking, when he had prevailed so far as to get the place spared if there were but ten righteous in it? Either, 1st, Because he could not in modesty proceed any further, and being a good man himself, he had a charitable opinion of others, and thought there must be so many good men in all those cities, especially including Lot and his family. 2d, Because he owned that it deserved to perish if there were not so many: as the dresser of the vineyard (Luke 13:9) consented that the barren fig-tree should be cut down if one year's trial more did not make it fruitful. Or, 3d, Which is most probable, because God restrained his spirit from asking any further. When God hath determined the ruin of a place, he forbids it to be prayed for. No doubt Abraham remembered Lot in his prayers; but his large and generous mind could not be content with Lot's preservation, but aims at the preservation of the whole city; which when he saw to be doubtful or unlikely, he prayed for Lot's deliverance out of the common destruction, as appears from Genesis 19:29.