Genesis 6:5

And God saw the wickedness of man was great in the earth,
&c.] That it spread throughout the earth, wherever it was inhabited by men, both among the posterity of Cain and Seth, and who indeed now were mixed together, and become one people: this respects actual transgressions, the wicked actions of men, and those of the grosser sort, which were "multiplied" ^F18 as the word also signifies; they were both great in quality and great in quantity; they were frequently committed, and that everywhere; the degeneracy was become universal; there was a flood of impiety that spread and covered the whole earth, before the deluge of waters came, and which was the cause of it: this God saw, not only by his omniscience, by which he sees everything, but he took notice of it in his providence, and was displeased with it, and determined in his mind to show his resentment of it, and let men see that he observed it, and disapproved of it, and would punish for it:

and [that], every imagination of the thoughts of his heart [was]
only evil continually:
the heart of man is evil and wicked, desperately wicked, yea, wickedness itself, a fountain of iniquity, out of which abundance of evil flows, by which it may be known in some measure what is in it, and how wicked it is; but God, that sees it, only knows perfectly all the wickedness of it, and the evil that is in it: the "thoughts" of his heart are evil; evil thoughts are formed in the heart, and proceed from it; they are vain, foolish, and sinful, and abominable in the sight of God, by whom they are seen, known, and understood afar off: the "imagination" of his thoughts is evil, the formation of them; they were evil while forming, the substratum of thought, the very beginning of it, the first motion to it, yea, "every" such one was evil, and "only" so; not one good among them, not one good thing in their hearts, no one good thought there, nor one good imagination of the thought; and so it was "continually" from their birth, from their youth upwards, throughout the whole of their lives, and all the days of their lives, night and day, and day after day, without intermission: this respects the original corruption of human nature, and shows it to be universal; for this was not only true of the men of the old world, but of all mankind; the same is said of men after the flood as before, and of all men in general without any exception, ( Genesis 8:21 ) ( Psalms 14:1-3 ) ( Romans 3:9-11 ) . Hence appears the necessity of regeneration, and proves that the new creature is not an improvement of the old principles of corrupt nature, since there is no good thing in man but what is put into him; also the disability of man to do that which is good, even to think a good thought, or do a good action; therefore the works of unregenerate men are not properly good works, since they cannot flow from a right principle, or be directed to a right end.