Bible Notes Online - Genesis 9 - ESV
Commentary

v1: Man's role on the earth remains, as Noah as his family are commanded to be fruitful. This command echoes the commend in 1.28, "be fruitful and increase in number; fill the earth and subdue it." To fill the earth means to spread out, not remain in one place. 

Compare Acts 1.8; where the Holy Spirit promises to equip God's people to take the good news of Christ into all the world.

v2: Fear and dread; enmity and authority and responsibility. There is no longer the harmony of man and beast, that allowed them to dwell in the ark for 370 days.

v3: The explicit provision, that man can eat animals as well as fruit and vegetables.

v4-6: The sanctity of human life; man's responsibility is to exercise judgment, especially over those who take the life of another; thus man carries out God's judgment. In Romans 13.1, the authorities are appointed by God, even in a society which is not theocratic.

We note that both Cain (Genesis 4:8) and Lamech (Genesis 4:23) were guilty of murder.

v7: Repeating v1; be fruitful, increase, multiply.

v8-9: God's covenant with Noah. The world that existed has been destroyed by water, 2 Peter 3.6. The fresh start required a new covenant.

v10-12: Noah is effectively the representative of man and beast, "very living creature with you." And both man and beast are accountable before God for bloodshed.

The scripture is clear that all living creatures outside the ark died, and that this covenant is with all living creatures who came from the ark. Here is hope and promise for the refilling of the earth. We note also that the earth will never again be destroyed by a flood.

v13-16: The rainbow in the cloud; the special reminder of God's mercy and faithfulness comes in difficult times. The rainbow is a reminder both to God and to man, although it is impossible that God should forget His covenant.

v17: The rainbow is the constant reminder of the perpetual covenant.

v18-19: Just as Eve was the mother of all living (Genesis 3.20), so the whole earth is populated from the three sons of Noah. This is consistent with the statement that everyone outside the ark died, Genesis 7:21-23.

v20-21: Even in times of blessing, things go wrong. There was nothing wrong in Noah planting a vineyard. Yet drunkeness is condemned in scipture. For Noah, a truly righteous man, this is an evidence of his human frailty

v22-23: Ham is careless, and dishonours his father by drawing attention to his father's shame. Shem and Japheth are more careful and discrete, and cover his shame.

Our part is to cover man's shame, not to gloat over his frailty, nor to expose his mistakes; any judgment is God's prerogative.

v24-25: As a result, Ham's descendants, particularly the Canaanite peoples, are cursed. This verse has been abused by some who have treated Hamitic peoples (Africans) as lesser, making them slaves. We might say that this curse is predictive of what would happen. But it is not justification for one tribe to treat another as slaves.

v26-29: Shem; the Semitic peoples, especially Jews; the Lord is the God of Shem.

Japheth, Gentiles, who may dwell in the tents of Shem; salvation is of the Jews, but Gentiles may enter in.