Technical note / Defect ('illah): (3) The word "'an" (from) dropped out of manuscripts (Z) and (B), which gave the false impression that "al-Mas'udi" is an ascription of Abu al-Nadr Hashim bin al-Qasim. Yet Abu al-Nadr is "Laythi" (from Banu Layth bin Kinanah), not Mas'udi.

Grading: (4) Its narrators are thiqah, but it is "mursal".
Technical note / Defect ('illah): (Inconsistency in the chain): In some sources al-Mas'udi ('Abd al-Rahman bin 'Abdullah) narrated this report directly from al-Qasim (Ibn 'Abd al-Rahman) without mentioning the intermediary of his brother "Abu 'Umays"; indeed in Ibn Sa'd [4/118] he even explicitly states that he heard it from al-Qasim. Perhaps al-Mas'udi, after his memory deteriorated, forgot whether this report was through his brother or not.
Important point: But the more apparent view is that it is "through his brother". For Zayd bin al-Hubab (whose hearing from al-Mas'udi is early) narrated it as "al-Mas'udi from his brother from Abu Ishaq al-Sabi'i", mentioning Abu 'Umays. Admittedly, Zayd named "Abu Ishaq al-Sabi'i" in place of al-Qasim. It is not unlikely that Abu 'Umays heard it from both. In any case, al-Mas'udi once expressed doubt about mentioning al-Qasim, so the narration via "Abu Ishaq al-Sabi'i" seems more likely (ashbah).

Reference / Source: Abu Nu'aym recorded it in "al-Hilyah" [9/39] via 'Abd al-Rahman bin Mahdi, from al-Mas'udi, with this same chain.

Reference / Source: Ibn Sa'd [4/126] and Ibn Abi Shaybah [3/316] recorded it from 'Abdullah bin Idris; Ibn Sa'd [4/126] from Yazid bin Harun; and al-Bukhari in "al-Tarikh al-Awsat" [1/405] and Ibn Abi 'Asim in "al-Ahad wa al-Mathani" (344) via Abu Mu'awiyah Muhammad bin Khazim. All three narrate it from al-Mas'udi, from al-Qasim bin 'Abd al-Rahman. They did not mention Abu 'Umays.
Technical note / Defect ('illah): But Ibn Abi Shaybah said in the narration of Ibn Idris: "I think (arahu) it is from al-Qasim", expressing doubt. And Ibn Idris is a Kufan whose hearing from al-Mas'udi is early.

Reference / Source: Al-Tabarani recorded it in "al-Kabir" [25/(427)], and from him Abu Nu'aym in "Ma'rifat al-Sahabah" (7979), via Zayd bin al-Hubab, from al-Mas'udi, from his brother 'Utbah (Abu 'Umays), from Abu Ishaq al-Sabi'i.
Important point: Zayd bin al-Hubab is a Kufan, and his hearing from al-Mas'udi was before his memory became confused (ikhtilat), i.e. early (like that of Abu Nu'aym and Waki'). So what is more likely in this report is that it is the narration of "Abu Ishaq al-Sabi'i", which al-Mas'udi narrates through his brother Abu 'Umays. And Allah knows best.