Commentary for Genesis 18:20

'ויאמר ה AND THE LORD SAID to Abraham, thus doing what he had said — that He would not conceal the matter from him.

AND THE ETERNAL SAID, THE CRY OF SODOM AND GOMORRAH. Rashi comments: “And the Eternal said to Abraham, thus doing what He had said, i.e., that He would not conceal the matter from him,”
And Rabbi Abraham ibn Ezra said that the verse, And the men turned from there,¹²⁹Verse 22 here. was inserted in the middle of the account¹³⁰According to Ibn Ezra, Verse 22, which states, And the men turned from there and went toward Sodom, and Abraham stood yet before the Eternal, actually took place before our present verse for it was after the angels had walked toward Sodom that G-d said to Abraham, The cry of Sodom and Gomorrah… However, Verse 22 was entered later in the account in order to let us know the time of G-d’s word to Abraham — the cry of Sodom and Gomorrah, etc. — was when they came to Sodom. in order to let us know that at the time the angels arrived in Sodom, then G-d said to Abraham: The cry of Sodom and Gomorrah is great.
The opinion of all commentators is likewise that G-d was speaking with Abraham. Now according to this, the correct interpretation of the verse, And the men turned from there,¹²⁹Verse 22 here. is that when G-d said to Abraham after the men journeyed from him, The cry of Sodom and Gomorrah is great, Abraham stood in prayer and supplication before Him to forgive them and to give him permission to speak. And he prolonged his prayer until the men came to Sodom, and then Abraham drew near and said, Wilt Thou also sweep away the righteous with the wicked?¹³¹Verse 23 here. Or the explanation may be that Scripture itself returns to clarify the expression, Abraham stood yet before the Eternal,¹³²Verse 22 here. According to this interpretation, Abraham did not pray before he began saying, Wilt Thou also sweep away. as meaning that Abraham drew near and said, Wilt Thou also sweep away the righteous with the wicked? Thus he prolonged his supplication before Him, saying each time, “Let not the anger of the Eternal blaze,”¹³³See Exodus 32:22. and directing the intent of his mind each time towards prophecy until he heard an answer to his words direct from the Holy One, blessed be He. They continued in this manner the entire day [until, as the verse says], the Eternal finished speaking with Abraham,¹³⁴Verse 33 here. and the two angels came to Sodom.

'ויאמר ה, the angel said to Avraham that G’d had said that He dispatched these messengers on account of the outcry in heaven over the sins of Sodom, a reference to what G’d had mentioned in 13,13.