The Source of Traditions on Imam al-Riḍā (Vol 2) · Hadith 103 (#Ḥadīth #103)

103 - وَبِهذَا الإِسنادِ قالَ: قالَ عَلِىُّ بْنِ أَبِي طالِبٍa.sُ: لا اعتِكافَ إِلاّ بِالصَّومِ.

31-103 According to the same documentation, Ali ibn Abi Talib said, “No one can go into seclusion in the mosque without fasting.”

Gradings are classical jarḥ-wa-taʿdīl, name-matched to a rijāl index (not individually re-verified).