Allamah Muhammad ibn Abdur Rahman Sakhaawi said in

“القول البديع في الصلاة على الحبيب الشفيع صلى الله عليه وسلم”:

[G] “It is narrated from Ali رضي الله عنه that he said, “The one who sends a hundred (100) salaat upon the Nabi ﷺ on the day of Jumuah, he will come on the Day of Judgement with such a noor (light) that if it was to be distributed amongst the creation it would encompass all of them.”

Collected by Abu Nuaim in ‘Al-Hilyah’. And he said, “Gharib.”

Explanation:

After narrating this hadith Abu Nu’aim said, “Gharib from the hadith of Ibrahim and Ibn A’jlaan. We did not write it but from the hadith of Muhammad ibn Ahmed Al-Bukhari.” [Hilyatul Awliyaa Vol.8 Pg.47]

Imam Baihaqi also collected this athar in his ‘Shu’abul Imaan’ with a slightly different wording and chain. Ali رضي الله عنه said, “Whoever sends salutations on the Prophet ﷺ on the the day of Jumu’ah a hundred times, he will come on the Day of Qiyamah and upon his face will be such a noor (light) that the people will ask, ‘What action did he used to do?’” [Shu’abul Imaan Vol.4 Pg.436] The editor said that there are narrators in the chain which he was unable to locate.