Explanation of the hadith
The Prophet (may Allah's peace and blessings be upon him) saw in a dream his cousin Ja‘far ibn Abi Tālib flying in Paradise with the angels. Therefore, he was called Ja‘far At-Tayyār, meaning "the flying Ja‘far", and Dhu al-Janāhayn, meaning "the one with the two wings". Ja‘far was martyred in the battle of Mu'tah after both his arms were cut off, so Allah, the Almighty, replaced them with two wings with which he flies with the angels in Paradise.