6:3 My spirit. One of the ministries of God’s Holy Spirit has always been to convict man’s spirit of “sin, and of righteousness, and of judgment” (John 16:8). Man is also “flesh,” however, and there is perpetual conflict between the flesh and the spirit, even in the life of a believer (Romans 8:5; Galatians 5:16,17). God is long-suffering with respect to man’s rebellion, but only for a time: the hour of His judgment must eventually arrive.

6:3 hundred and twenty years. This prophecy was apparently given, perhaps through Methuselah, just 120 years before the coming Flood. The prophet Enoch had already been translated. Shem, Ham and Japheth had not yet been born and God’s specific commands to Noah (Genesis 5:32; 6:10,13,21) not yet given.