Abu Ja`far (as) said: There was a young boy from the Jews who would follow the Prophet (sawa) so much that he (sawa) had a liking for him*, and would send him for duties, and would write books for his people.
One day he (the young Jew) went missing, so the Prophet (sawa) asked about him, to he (sawa) was told by him by someone: “I left him in the last day of his days on Earth.”
So the Prophet (sawa) went to him along with his companions, and a blessing was when he (sawa) would speak to someone they would always reply.
So he said: “Oh so-and-so”, so he (the young Jew) opened his eyes and said: “Labayka ya Abal-Qasim.”
The Prophet said (sawa): “Ash-hado anna laa illaha illa-Allah, wa ana Rasool Allah.” (I bear witness that there is no deity other than Allah, and I am his Messenger).
So the Young Jew looked at his father and did not say anything…
So the Prophet (sawa) called upon him again a second time and said as he said the first (the Shahaada/Testimony).
So the Young Jew ran to his father and did not say anything…
So the Prophet (sawa) called upon him a third time and the boy again ran towards his father..
So his father said (to the Young Jew): “If you desire to say it, then say it, and if you desire not to, then don’t.”
So the Young Jew said: “Ash-hado anna laa illaha illa-Allah, wa anaka Muhammadan Rasool Allah.” (I bear witness that there is no deity other than Allah, and you, Muhammad, is His Messenger).
He then died in that spot.
So the Prophet (sawa) said to his father: “Leave from him.” and then said to his companions “Wash him, Prepare him for burial, and between you pray over him”
He (sawa) then left saying: “All praise is due to Allah who saved him today from the fire.”
Sanad: al-Sadooq, from his father, from Sa’ad bin Abd-Allah, from Ahmed bin Muhammad bin Eassa, from Muhammad bin Khaled, from Ahmed bin al-Nadhr al-Khazaaz, from Amro bin Shimr, from Jabir who said the above hadith
Source: al-Amaali al-Sadooq, Assembly #62, Hadith #10
* In other manuscripts (such as al-Amaali al-Toosi) it is to be translated as he got annoyed from him.