From Genesis: Interpretation:

c. If the beginning of the flood narrative claimed only that, the text would be
flat and one-dimensional. But there are two other matters here that enrich and
greatly complicate the beginnings. First, with amazing boldness the narrative
invites the listening community to penetrate into the heart of God (vv. 67).
What we find there is not an angry tyrant, but a troubled parent who grieves
over the alienation. He is growingly aware that the “imagination of the
thoughts” of the human heart are unrelievedly hostile (v. 5). The conjuring,
day dreams, and selfperceptions of the world are all tilted against God’s
purpose. God is aware that something is deeply amiss in creation, so that God’s
own dream has no prospect of fulfillment. With that perverted imagination,
God’s world has begun to conjure its own future quite apart from the future
willed by God (cf. 11:6).

As a result, verse 6 shows us the deep pathos of God. God is not angered but
grieved. He is not enraged but saddened. God does not stand over against but
with his creation. Tellingly, the pain he bequeathed to the woman in 3:16 is
now felt by God. Ironically, the word for “grieve” (‘asav) is not only the same as
the sentence on the woman (“pain” 3:16), but it is also used for the state of
toil from which Noah will deliver humanity (5:29). The evil heart of humankind
(v. 5) troubles the heart of God (v. 6). This is indeed ”heart to heart” between
humankind and God. How it is between humankind and God touches both
parties. As Ernst Würthwein suggests, it is God who must say, “I am undone”
(cf. Isa. 6:5; Wort und Existenz, 1970, pp. 313).