How is Genesis 6.6 to be explained?

There are several figures of speech in the Bible that accommodate the human level of understanding. One is anthropomorphism (man form), where physical features are ascribed to God, e.g., the eyes of the Lord (1 Pet. 3.12), Jehovah’s arm (Jn. 12.38), etc. These depict God’s watchfulness and his power.

There is another figure called anthropopathism (man feeling), whereby human emotions are sometimes attributed to God. To say, therefore, that God “repented,” or that he was “grieved,” is simply a symbolic way of asserting that man’s conduct did not meet the divine standard. This language vividly portrays, from a human perspective, God’s displeasure at our rebellion.

Underline “repented” and “grieved,” and in your margin note: Human emotions figuratively ascribed to God.