Hadith 6:933
Abu Bakr narrated to us, he said: Sharik narrated to us, from Jabir, from Abu Ja’far, Salim, and al-Qasim: They said: The grave of the Prophet, peace and blessings of Allah be upon him, and [the graves of] Abu Bakr and Umar were mounds facing the Qibla.
حدثنا أبو بكر قال ثنا شريك عن جابر عن أبي جعفر وسالم والقاسم قالوا كان قبر النبي صلى الله عليه وسلم وأبي بكر وعمر جثا قبلة