הֵן־בְּעָו֥וֹן חוֹלָ֑לְתִּי וּ֝בְחֵ֗טְא יֶֽחֱמַ֥תְנִי אִמִּֽי׃
Purifícame con hisopo, y será limpio: Lávame, y seré emblanquecido más que la nieve.
Rashi on Psalms
Behold, with iniquity I was formed Now how could I not sin when the main part of my creation was through coitus, the source of many iniquities? Another explanation: The main part of my creation is from a male and a female, both of whom are full of iniquity. There are many midrashim to this verse, but they do not fit the context of the psalm.
Rashi on Psalms
conceived me Heb. יחמתני, an expression of heat, as (Gen. 30:38): “And they came into heat (ויחמנה) when they came to drink.”