By faith Noah, being warned of God of things not seen as yet, moved with fear, prepared an ark to the saving of his house; by the which he condemned the world, and became heir of the righteousness which is by faith. By faith Noah - See the whole of this history, Genesis 6:13.
Warned of God - Χρηματισθεις. As we know from the history in Genesis that God did warn Noah, we see from this the real import of the verb χρηματιζω, as used in various parts of the New Testament; it signifies to utter oracles, to give Divine warning.
Moved with fear - Ευλαβηθεις· Influenced by religious fear or reverence towards God. This is mentioned to show that he acted not from a fear of losing his life, but from the fear of God; and hence that fear is here properly attributed to faith.
He condemned the world - He credited God, they did not; he walked in the way God had commanded, they did not; he repeatedly admonished them, 1 Peter 3:20, they regarded it not; this aggravated their crimes while it exalted his faith and righteousness. "His faith and obedience condemned the world, i.e. the unbelievers, in the same sense in which every good man's virtues and exhortations condemn such as will not attend to and imitate them." Dodd.
Became heir of the righteousness - He became entitled to that justification which is by faith; and his temporal deliverance was a pledge of the salvation of his soul.