Ali bin Abu Talib reported,

I washed the Prophet ﷺ, and I looked carefully to see if anything would come from the deceased as happens with others, but I saw nothing. He was pure ﷺ, in life and in death.Four people, and no others, took charge of his burial and laying him to rest, Ali, Abbas, Fadl, and Salih the freed slave of the Messenger of Allah ﷺ. A side niche was dug for the Messenger of Allah ﷺ, and mud bricks were set up over him.

Azami 3803

Sahih

عن علي بن أبي طالب قال

غسلت النبي ﷺ فذهبت لأنظر ما يكون من الميت فلم أر شيئا، وكان طيبا ﷺ حيا وميتا، وولي دفنه وإجنانه دون الناس أربعة: علي والعباس والفضل وصالح مولى رسول الله ﷺ و لحد لرسول الله ﷺ لحدا، ونصب عليه اللبن نصبا.

الأعظمي 3803صحيح
Contents
Reference
Commentary
Ayat
Collection
Jami al-Kamil
Book
Funerals
Chapter
Graves
Section
Niche grave and placing bricks over the deceased
Numbering
Jami al-Kamil 3803 (2nd edition)
Azami 3803