In T.B. P'sachim, fol. 54, col. 1, it is said that the reason of
the omission of the words, "And God saw that it was good," in
respect to the second day of the creative week, was because
hell-fire was then created; but see the context.
When Adam saw (through the Spirit) that his posterity would be condemned
to Gehenna, he disobeyed the precept to procreate. But when he perceived
that after twenty-six generations the Israelites would accept the law,
he bestirred himself in compliance; as it is said (Gen. iv. 1), _Adam
vero cognovit uxorem suam Hevam_.
THE MIDRASHIM, _Yalkut_.