The Book of Occultation — al-Ṭūsī · Hadith 121 (#Ḥadīth #38)

61- قال: وروى علي بن معاذ قال: قلت لصفوان بن يحيى: بأي شيء قطعت على علي؟قال: صليت ودعوت الله واستخرت عليه وقطعت عليه.

H 61 - Ali bin Maaz narrated: I asked Safwan bin Yahya: Through which reasoning have you adopted faith in the Imamate of Imam Musa Kadhim ? He replied: I prayed the ritual prayer and after that sought counsel (Istikhara) from Almighty Allah and the result was that I got certainty about it.

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