The Source of Traditions on Imam al-Riḍā (Vol 2) · Hadith 332 (#Ḥadīth #332)

332 - وَبِهذَا الإسناد قالَ كانَ رَسُولَ اللَّهِ صَلَّى اللهُ عَلَيْهِوَآلِهِ إِذا دَخَلَ شَهْرِ شَعْبانَ يصومه فِي أَوَّلُهُ ثَلاثاً وَفِي وسطه ثَلاثاً وَفِي آخِرَه ثَلاثاً وَإِذا دَخَلَ شَهْرِ رَمَضان يفطر قَبْلِهِ بيومين ثُمَّ يصوم.

31-332 According to the same documentation, it has been narrated that whenever the (Arabic) month of Sha’ban arrived, God’s Prophet (S) fasted three days in the beginning, three days in the middle and three days near the end of that month. He would not fast when two days were left before the (Arabic) month of Ramadhan. Then whenever Ramadhan came, he fasted.”

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