(Rav Huna citing R. Avahu): There is no forgetting in front of Hash-m. It is as if for the sake of Yisrael, Hash-m becomes forgetful (he overlooks one Aveirah, in order that merits will outweigh Aveiros). What is the reason? "Nosei Avon" is written [lacking a Vov, like] 'Nasa' (like Nashisi, which refers to forgetting).

Support: Similarly, David said "Nasasa Avon Amecha Kisisa Chol Chatasam Sela."