Hadith 6:932
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 Abu Bakr and Umar was a mound facing the Qibla. Bricks were set up for them [as a covering].
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 نصب لهم اللبن نصبا