The Book of Moses claims that Enoch wept after seeing the wicked in the time of Noah. Moses 7:44 reads:
And as Enoch saw this, he had bitterness of soul, and wept over his brethren, and said unto the heavens: I will refuse to be comforted; but the Lord said unto Enoch: Lift up your heart, and be glad; and look.
This is similar to that of 2 Enoch 41:1 which reads:
And I (Enoch) sighed and burst into tears, and I said concerning their disreputable depravity, Oh how miserable . . ..
Where did Joseph Smith find out about this part of the Enoch story?