Charles Ellicott Commentary Genesis 6:5

"And Jehovah saw that the wickedness of man was great in the earth, and that every imagination of the thoughts of his heart was only evil continually." — Genesis 6:5 (ASV)

And God saw. —Really, And Jehovah saw.

Imagination. —More exactly, form, shape. Thus, every idea or embodied thought which presented itself to the mind through the working of the heart—that is, the whole inner nature of man—was only evil continually—in Hebrew, all the day,—from morning to night, without reproof of conscience or fear of Divine justice.

A more forcible picture of complete depravity could scarcely be drawn; and this corruption of man’s inner nature is ascribed to the overthrow of moral and social restraints.