Note / Clarification: In the manuscripts this name has been distorted into "Rawh" (with the letter ha'), whereas it is with the letter qaf (Rawq); he is 'Atiyyah bin al-Harith al-Hamdani (Abu Rawq).

Grading: It is "sahih"; the mawla of 'Ali, although "unnamed" (mubham), has been corroborated. In our manuscripts the name appears as "'Ali bin Rabi' al-Ansari", whereas in "Ithaf al-Mahara" of al-Hafiz (4280) it appears as "'Ali bin al-Haytham". In this generation there is "'Ali bin al-Haytham al-Baghdadi" (known as Sahib al-Ta'am), one of the teachers of al-Bukhari. The same variation also occurs in Tammam bin Muhammad al-Razi's "Fawa'id" (1463 and 1464) in the narration of Yahya bin Durust: once he said "'Ali bin Rabi'" and the other time "'Ali bin al-Haytham". The apparent conclusion is that this is one and the same person (and Allah knows best), sometimes attributed to his father and sometimes to his grandfather.
Technical note: If this is established, then Ibn Hibban said about 'Ali bin Rabi': "Munkar reports are many in his narration, so using him as proof is invalid." Al-'Uqayli mentioned him among the weak narrators under the name "'Ali bin Nafi'" and said: "He is unknown in transmission; his hadith is not preserved (ghayr mahfuz)." But Imam al-Bukhari narrated from him in his "Sahih" under the name "'Ali bin al-Haytham". Allah knows best. In any case he is "corroborated" (mutaba').

Reference / Source: Ibn Abi Shaybah (3/ 301) narrated it from Hafs bin Ghiyath, from 'Atiyyah bin al-Harith Abu Rawq, from a mawla of al-Hasan bin 'Ali.

Reference / Source: Abu al-Qasim al-Baghawi narrated it in "Mu'jam al-Sahabah" (1826), and Abu Bakr al-Qati'i (941) and Ibn 'Asakir (42/ 564), from Salm bin Junadah, from Hafs, with this chain (in the printed editions of these three books there are distortions in this chain). Also Ibn Sa'd (3/ 36), al-Baladhuri (3/ 257), Ibn Abi al-Dunya (79) and Ibn 'Asakir narrated it via 'Amir al-Sha'bi; Ibn Sa'd and al-Baladhuri via Kulayb bin Shihab; and Ibn al-Mundhir (3120), al-Tahawi (1/ 500) and Ibn 'Asakir via Abu Ishaq al-Sabi'i; all of them said: "Al-Hasan bin 'Ali said four takbirs over 'Ali (at his funeral prayer)." All their chains are "sahih".

Preponderant view: In al-Tabarani's "al-Kabir" (168) there is a mursal narration that al-Hasan said "nine" (9) takbirs over him, but what preceded, that he said "four" takbirs, is stronger and better established.