for he states in al-Rawḍ (362): “Ibrāhīm ibn Ṣāliḥ al-Shīrāzī narrated to us—in Mecca in the year 283 AH, the year in which he died—Ḥajjāj ibn Nuṣayr narrated to us …” and so on.
It appears to me that he was not among al-Ṭabarānī’s well-known shaykhs, for he narrated only rarely from him. In al-Muʿjam al-Awsaṭ (3/447/2959), he narrated from him only one hadith, and in al-Duʿāʾ, two hadiths (nos. 160 and 1141).
However, it appears that the hadith was known through ʿUthmān ibn al-Haytham, for some hadith masters cited it on his authority. Ibn Abī Ḥātim said in al-ʿIlal (1/353/1041):
“I asked my father about a hadith narrated by ʿUthmān al-Muʾadhdhin from his father … and he mentioned it. My father said: ‘Ḥammād narrated it from ʿĀṣim, from Abū Wāʾil … from the Prophet, peace and blessings be upon him.’ I asked my father: ‘Which of the two is correct?’ He replied: ‘Al-Haytham ibn Jahm has been corroborated in this connected version of the narration.’”
Imām al-Dāraquṭnī likewise cited it without its full chain. In al-ʿIlal (5/58), after mentioning it through the route of Isḥāq ibn Abī Isrāʾīl, from Ḥammād, from ʿĀṣim, from Zirr, from ʿAbd Allāh, attributed to the Companion, he said: “Zāʾidah and al-Haytham ibn Jahm al-Baṣrī—the father of ʿUthmān ibn al-Haytham al-Muʾadhdhin, trustworthy and acceptable (1)—narrated it from ʿĀṣim, from Abū Wāʾil, from ʿAbd Allāh, attributed to the Prophet. Perhaps ʿĀṣim retained it from both of them. And Allah knows best.”
Shaykh Aḥmad Shākir judged the chain of transmission of the hadith to be authentic in his annotations to al-Musnad (6/40), and said: