Who is Jabir ibn Abdullah ibn Haram, and is it true what was said that the Messenger of Allah (peace and blessings be upon him) dug Jabir's grave and slept in it the night he was buried until morning?

Jābir ibn ‘Abdullāh ibn ‘Amr ibn Harām did not die during the lifetime of the Messenger of Allāh, peace and blessings be upon him; rather, he passed away in the year 77 or 78 AH. The one who died during the Prophet’s lifetime, peace and blessings be upon him, was his father, ‘Abdullāh ibn ‘Amr ibn Harām, who was martyred on the Day of Uhud. There is no text stating that the Messenger of Allāh, peace and blessings be upon him, stood at ‘Abdullāh’s grave to bless him. Instead, he prayed over him and buried him and ‘Amr ibn al-Jamūḥ in a single grave. Six months later, Jābir moved his father to a separate grave, and then moved him again forty-six years later due to a flood, finding him exactly as he was on the day he was buried, with nothing changed except for a small part of his ear.