Genesis 18

The Lord's visit to Abraham set the time for Isaac's birth. The three visitors were probably the Lord and two angels (see study note on 16:7). Abraham welcomed the visitors peacefully and generously, which contrasted with the chaos and corruption in Sodom (chapter 19).

Sharing a meal was important for making or confirming covenants. When God was ready to fulfill the covenant promise, he personally shared a meal with Abraham. Fellowship with God has always included a communal meal (see Exodus 24:9–11; Matthew 26:17–30 // Luke 22:7–38; Acts 2:42; 1 Corinthians 11:20–34).

Abraham received his visitors as very important guests, perhaps realizing that they were messengers from God.

My lord: The Hebrew text uses ’adonay, which always refers to God. In Hebrew tradition, people said this word when they saw the letters of God's holy name ("Yahweh") in the text. The text here might use ’adonay instead of the more common ’adoni to show this was the angel of the Lord, meaning the Lord himself (see study note on 16:7). We do not know if Abraham knew who his visitors were at first. But by the end of the story, he knew he had been talking with God.

The visitors asked about Sarah by name, even though no one had told them who she was.

I will surely return: The Hebrew phrase is emphatic. The statement announced a certain promise and dramatic change.

Sarah thought no one noticed her disbelieving laughter. But God knows what people do in secret and what they feel (see Psalm 69:5; Proverbs 20:27; Mark 4:22; Luke 8:43–48; Hebrews 4:13). He knows if they doubt promises or trust in him (see Hebrews 11:11–12).

Is anything too difficult for the LORD?: This question does not expect an answer. It teaches that nothing is too difficult for God.

God can do great and surprising things. For those who live in covenant (a binding promise relationship) with him, nothing is impossible, because nothing is too hard for the Lord.

God trusted Abraham as his prophet (18:16–21; see 20:7). In return, Abraham pleaded that God would save Sodom (18:23–32; see Hebrews 7:23–26). God can do anything he wants. This passage confirms it will be fair and right.

Abraham was responsible for teaching his descendants to be righteous and act justly so they might enjoy God's blessings. It was important for Abraham to know how God’s righteousness was at work in judgment.

The outcry: See Ezekiel 16:49–50.

God, who knows everything, was cautious in his judgment. He knew the sins of Sodom and Gomorrah. This careful examination showed God's justice in a way humans could understand. He would not destroy the people unless he was certain they were wicked.

Abraham probably thought there were more righteous people in Sodom and Gomorrah than there were (see study note on 19:14). Concerned for them, he made a legal appeal to the Lord based on God's justice. His prayer might seem bold, as if he were negotiating with God. But he approached God with true humility and respect. He did not try to convince God to act against his will. Instead, he prayed for the well-being of others (compare with Lot’s prayer, 19:18–23).

God is a fair judge. "Righteousness exalts a nation" (Proverbs 14:34). Righteous people help preserve society (compare Matthew 5:13).