And the LORD was sorry that he had made man on the earth, and it grieved him to his heart.
All Commentaries on Genesis 6:6 Go To Genesis 6
George Leo Haydock
It repented him God, who is unchangeable, is not capable of repentance, grief, or any other passion. But these expressions are used to declare the enormity of the sins of men, which was so provoking as to determine their Creator to destroy these his creatures, whom before he had so much favoured. (Challoner)
God acted outwardly as a man would do who repented. (Haydock)