Virtues of Ja'far bin Abi Talib bin Abd al-Muttalib bin Hashim (may Allah be pleased with him): he was martyred at Mu'tah in the year 8 AH

It is narrated from Sayyiduna Anas (may Allah be pleased with him); he said: My paternal aunt's son Harithah went out on the day of Badr only to observe, not to fight, but an arrow struck him and he was martyred. My aunt came to the Messenger of Allah (peace and blessings be upon him) and said: O Messenger of Allah, my son Harithah: if he is in Paradise, I will be patient and hope for reward; otherwise, you will see what I do. He (peace and blessings be upon him) said: "O Umm Harithah, there are many gardens there, and indeed Harithah is in the highest station of the Paradise of al-Firdaws."
This hadith is sahih (authentic) on the condition of Imam Muslim, but the two Shaykhs (Bukhari and Muslim) did not record it with this wording narrated by Thabit; however, they both agreed on the abridged hadith narrated by Humayd from Anas.

Abdullah bin Muhammad bin Umar bin Ali narrates from his father that a Roman man struck Ja'far bin Abi Talib (may Allah be pleased with him) with such force that he was cut into two pieces. One half of him fell into a vineyard, and thirty or somewhat more than thirty wounds were found on that half of his body. He had migrated to Abyssinia in the second emigration together with his wife Asma' bint Umays, and remained there until the Messenger of Allah (peace and blessings be upon him) had migrated to Madinah. Then he came to him (peace and blessings be upon him) when he (peace and blessings be upon him) was at Khaybar, and the Messenger of Allah (peace and blessings be upon him) said: "I do not know which of the two makes me happier: the conquest of Khaybar or the arrival of Ja'far?" The narrator said: Ja'far's kunyah was Abu Abdullah.

Yahya bin Abbad bin Abdullah narrates from his father and grandfather: The man from Banu Murrah who had nursed me told me: It is as if I am looking at Ja'far bin Abi Talib on the day of the Battle of Mu'tah; he dismounted from his horse, hamstrung it, then advanced towards the enemy and fought until he was martyred.