Whole chapter discussed by Augustine of Hippo —
The Three Visitors
1Then the LORD appeared to Abraham by the Oaks of Mamre in the heat of the day, while he was sitting at the entrance of his tent. 2And Abraham looked up and saw three men standing nearby. When he saw them, he ran from the entrance of his tent to meet them and bowed low to the ground.
3“My lord,” said Abraham, “if I have found favor in your sight, please do not pass your servant by. 4Let a little water be brought, that you may wash your feet and rest yourselves under the tree. 5And I will bring a bit of bread so that you may refresh yourselves. This is why you have passed your servant’s way. After that, you may continue on your way.”
“Yes,” they replied, “you may do as you have said.”
6So Abraham hurried into the tent and said to Sarah, “Quick! Prepare three seahs of fine flour, knead it, and bake some bread.”
7Meanwhile, Abraham ran to the herd, selected a tender and choice calf, and gave it to a servant, who hurried to prepare it. 8Then Abraham brought curds and milk and the calf that had been prepared, and he set them before the men and stood by them under the tree as they ate.
Sarah Laughs at the Promise
9“Where is your wife Sarah?” they asked.
“There, in the tent,” he replied.
10Then the LORD said, “I will surely return to you at this time next year, and your wife Sarah will have a son!”
Now Sarah was behind him, listening at the entrance to the tent. 11And Abraham and Sarah were already old and well along in years; Sarah had passed the age of childbearing. 12So she laughed to herself, saying, “After I am worn out and my master is old, will I now have this pleasure?”
13And the LORD asked Abraham, “Why did Sarah laugh and say, ‘Can I really bear a child when I am old?’ 14Is anything too difficult for the LORD? At the appointed time I will return to you—in about a year—and Sarah will have a son.”
15But Sarah was afraid, so she denied it and said, “I did not laugh.”
“No,” replied the LORD, “but you did laugh.”
Abraham Intercedes for Sodom
16When the men got up to leave, they looked out over Sodom, and Abraham walked along with them to see them off.
17And the LORD said, “Shall I hide from Abraham what I am about to do? 18Abraham will surely become a great and powerful nation, and through him all the nations of the earth will be blessed. 19For I have chosen him, so that he will command his children and his household after him to keep the way of the LORD by doing what is right and just, in order that the LORD may bring upon Abraham what He has promised.”
20Then the LORD said, “The outcry against Sodom and Gomorrah is great. Because their sin is so grievous, 21I will go down to see if their actions fully justify the outcry that has reached Me. If not, I will find out.”
22And the two men turned away and went toward Sodom, but Abraham remained standing before the LORD.
23Abraham stepped forward and said, “Will You really sweep away the righteous with the wicked? 24What if there are fifty righteous ones in the city? Will You really sweep it away and not spare the place for the sake of the fifty righteous ones who are there? 25Far be it from You to do such a thing—to kill the righteous with the wicked, so that the righteous and the wicked are treated alike. Far be it from You! Will not the Judge of all the earth do what is right?”
26So the LORD replied, “If I find fifty righteous ones within the city of Sodom, on their account I will spare the whole place.”
27Then Abraham answered, “Now that I have ventured to speak to the Lord—though I am but dust and ashes— 28suppose the fifty righteous ones lack five. Will You destroy the whole city for the lack of five?”
He replied, “If I find forty-five there, I will not destroy it.”
29Once again Abraham spoke to the LORD, “Suppose forty are found there?”
He answered, “On account of the forty, I will not do it.”
30Then Abraham said, “May the Lord not be angry, but let me speak further. Suppose thirty are found there?”
He replied, “If I find thirty there, I will not do it.”
31And Abraham said, “Now that I have ventured to speak to the Lord, suppose twenty are found there?”
He answered, “On account of the twenty, I will not destroy it.”
32Finally, Abraham said, “May the Lord not be angry, but let me speak once more. Suppose ten are found there?”
And He answered, “On account of the ten, I will not destroy it.”
33When the LORD had finished speaking with Abraham, He departed, and Abraham returned home.