And the LORD said, "Because the outcry against Sodom and Gomorrah is great, and because their sin is very grave,
Genesis 18:20
Surrounding context
18:19 For I have known him, in order that he may command his children and his household after him, that they keep the way of the LORD, to do righteousness and justice, that the LORD may bring to Abraham what He has spoken to him."
18:20 And the LORD said, "Because the outcry against Sodom and Gomorrah is great, and because their sin is very grave,
18:21 I will go down now and see whether they have done altogether according to the outcry against it that has come to Me; and if not, I will know."