Charles Ellicott Commentary Genesis 7:1

"And Jehovah said unto Noah, Come thou and all thy house into the ark; for thee have I seen righteous before me in this generation." — Genesis 7:1 (ASV)

Come thou. —The task of building the ark is over, and after a week, to be spent in collecting animals and birds, Noah is to dwell in it. Many commentators suppose that 120 years were spent in the work; but this view arises from an untenable interpretation of Genesis 6:3, which really fixes the future duration of human life.