Psalm 51 (KJV)
5 Behold, I was shapen in iniquity; and in sin did my mother conceive me.
6 Behold, thou desirest truth in the inward parts: and in the hidden part thou shalt make me to know wisdom.
And in sin did my mother conceive me - Margin, as in Hebrew, “warm me.” This language simply traces his sin back to the time when he began to exist. The previous expression traced it to “his birth;” this expression goes back to the very beginning of “life;” when there were the first indications of life. The idea is, “as soon as I began to exist I was a sinner; or, I had then a propensity to sin - a propensity, the sad proof and result of which is that enormous act of guilt which I have committed.”