Al-Ṭabarānī recorded it in al-Kabīr. This is how it appears in the original of Ṣifat al-Ṣalāh, without mention of the volume or page number, so I do not know where I copied it from at that time!

Ismāʿīl al-Bajalī and Thuwayr ibn Abī Fākhtah are both weak.

The hadith has a corroborating report from Ibn Masʿūd, narrated by ʿAbd al-Malik ibn al-Walīd ibn Maʿdān, from ʿĀṣim ibn Bahdalah, from Abū Wāʾil, from him. He said:

“I cannot enumerate how often I heard the Messenger of Allah (peace and blessings be upon him) recite …” to the end of the hadith, including the additional wording.

It was recorded by al-Tirmidhī (431), Ibn Mājah (1166), Ibn Naṣr as well, and al-Ṭaḥāwī (1/175–176). Al-Tirmidhī said:

“This is a singular hadith; we know it only through the narration of ʿAbd al-Malik ibn Maʿdān.”

I say: He is weak, as stated in al-Taqrīb. Al-Dhahabī said in his book al-Mughnī:

“They declared him weak.”5

There is another corroborating report, but its chain of transmission contains Aṣram ibn Ḥawshab, who narrates it through his chain from ʿAbd Allah ibn Jaʿfar with similar wording.

Al-Ṭabarānī recorded it in al-Muʿjam al-Awsaṭ (8/373), among a set of hadiths with this chain, under no. 7757, and stated that it is narrated only through this chain.

I say: It is very weak. This Aṣram is abandoned and accused; he is therefore among those whose reports cannot be cited even as corroboration.

What I can conclude from this documentation and investigation is that the hadith is authentic in itself, or authentic through supporting evidence when all its chains from Ibn ʿUmar and its corroborating report from Ibn Masʿūd are considered together. The former is more likely in my view, since the three trustworthy narrators concurred in narrating it from Abū Isḥāq al-Sabīʿī, from Mujāhid, from Ibn ʿUmar.