Genesis 18:19

For I know him, that he will command his children and his household after him, and they shall keep the way of the Lord to do justice and judgment, that the Lord may bring upon Abraham that which he hath spoken of him. These words of the Lord were apparently addressed to the angels. The question was whether He should let Abraham know at once that the destruction of Sodom and Gomorrah was an act of His avenging justice. He had destined Abraham to be not only the father of a great and mighty nation, the children of Israel, but also the spiritual father of the true Israel of all times. Besides, Abraham not only led a life conforming to the will of the Lord for himself, but the Lord also knew, in prevenient love, and had chosen him for that purpose, that he would teach his children and all his progeny carefully to keep the way of Jehovah, of true piety, to exercise righteousness and judgment, and the Lord could thus fulfill all His promises upon them. Thus the destruction of Sodom and the surrounding country should be before the eyes of the children of Israel always as a monument of God's avenging justice, as an example of the end of the wicked. In revealing to Abraham the reason for the destruction of the wicked cities, the Lord wanted Abraham to see the justice of the punishment, which no intercession could hope to turn aside.