Majma al-Zawaid — Hadith 17577

Sayyiduna Abu Umamah (may Allah be pleased with him) transmits this saying of the Prophet (peace and blessings be upon him): "The angel on the right is a trustee over the angel on the left. When the servant does a good deed, the angel on the right records it as ten times over (in good deeds). And if the servant commits an evil deed and the angel on the left begins to record it, the angel on the right says to him: Refrain from recording it. So he (the angel on the left) refrains with regard to that evil deed. If the servant seeks forgiveness, that evil deed is not recorded, and if the servant stays silent (that is, does not seek forgiveness), it is recorded against him (as one evil deed)."
Al-Tabarani recorded it; its chain contains a narrator, Ja'far bin al-Zubayr, who is a kadhdhab (liar), but
this report agrees with the report before it, and there is nothing additional in it except that a good deed is recorded ten times over, and the Qur'an and the Sunnah indicate this (that it is so).