Q-Often we hear people narrating an incident that Nabi (sallallahu ‘alayhi wa sallam) once saw the Janazah of a Jew passing. Nabi (sallallahu ‘alayhi wa sallam) was very sad/cried and commented something to the effect that he is also of my Ummah. Please advice regarding the status of this narration.
Have not come across a Hadith which states that Nabi (sallallahu ‘alayhi wa sallam) was extremely saddened/wept when he saw the funeral of a Jew.
The closest Hadiths I could find are the following:
1) ‘Abdur Rahman ibn Abi Layla (rahimahullah) reports, “Sahl ibn Sa’d and Qays ibn Hunayf (radiyallahu ‘anhuma) were sitting in Al Qadisiyyah when a funeral procession passed by them and they stood up for it. Someone told them, ‘It is [the funeral] for one of the people of the land’ [i.e. one of the dhimmi– a non Muslim citizen living in an Islamic state]. They said, ‘A funeral procession passed by Nabi (sallallahu ‘alayhi wa sallam) and he stood up. He was told that it was the funeral of a Jew and he (sallallahu ‘alayhi wa sallam) said, ‘Is it not a soul/human?'”(Sahih Bukhari, Hadith: 1312, Sahih Muslim, Hadith: 961)
2) Sayyiduna Anas (radiyallahu ‘anhu) said: “A Jewish boy who used to serve Nabi (sallallahu ‘alayhi wa sallam) became ill. Nabi (sallallahu ‘alayhi wa sallam) went to visit him. He sat at his head and said to him, ‘Become a Muslim.’ He looked at his father who was present. His father said to him, ‘Obey Abul Qasim (sallallahu ‘alayhi wa sallam).’ So he accepted Islam. Nabi (sallallahu ‘alayhi wa sallam) left saying, ‘Praise be to Allah who has saved him from the Fire.'(Sahih Bukhari, Hadith: 1356)
And Allah Ta’ala Knows best
https://hadithanswers.com/nabi-sallallahu-alayhi-wa-sallam-and-the-funeral-of-a-jew/