It was narrated to me by Moḥammed bin al-Ḥassan, who said – it was narrated to me by Moḥammed bin al-Ḥassan al-Ṣaffār, from Ibrāhīm bin Hāshim, from ʿAmru bin ʿUthmān, from Jarrāḥ al-Ḥathā’, from Samāʿa bin Mahrʿān, who said:

Abū al-Ḥassan Mūsa عليه السلام said: Whoever performs ablution for Maghrib, that ablution becomes an atonement for what has passed of his sins during the day, except for the great sins (al-Kabā’ir).
Furthermore, whoever performs ablution for Morning prayers, that ablution becomes an atonement for him for what has passed of his sins during the night, except for for the great sins (al-Kabā’ir).

حدثني محمد بن الحسن قال حدثني محمد بن الحسن الصفار عن إبراهيم ابن هاشم عن عمرة بن عثمان عن جراح الحذاء عن سماعة بن مهران قال : قال أبو الحسن موسى عليه السلام من توضأ للمغرب كان وضوءه ذلك كفارة لما مضى من ذنوبه في نهاره ما خلا الكباير ، ومن توضأ لصلاة الصبح كان وضوءه ذلك كفارة لما مضى من ذنوبه في ليلته ما خلا الكباير