Psa 51:5 Behold, I was brought forth in iniquity, and in sin did my mother conceive me.
Walter Brueggemann writes:
c) The statement of verse 5 can be readily misunderstood . It does not mean that sex is sinful, nor that this speaker has a perverted beginning, or that the mother is morally implicated . Rather the speaker asserts that he is utterly guilty, in principle, from the beginning. There never was a time when this speaker was not so burdened . I take this to be not a clinical statement, but an expression of theological candor as the speaker exposes himself to God’s righteousness. One may say that it is a piece of liturgical hyperbole, as is much of the Psalms. We do not need to take the statement ontologically as a ” doctrine of man . ” What is important is that in this moment of drastic confrontation, the speaker has no claim . There is indeed ” no health in him . “
My understanding is the following: https://crosstheology.wordpress.com/what-about-davids-mother/