سنن أبي داود

Narrated Al-Qasim ibn Muhammad ibn AbuBakr:

I said to Aisha! Mother, show me the grave of the Messenger of Allah (ﷺ) and his two Companions (Allah be pleased with them). She showed me three graves which were neither high nor low, but were spread with soft red pebbles in an open space.

Abu 'Ali said: It is said that the Messenger of Allah (ﷺ) is forward, Abu Bakr is near his head and 'Umar is near is feet. His head is at the feet of the Messenger of Allah (ﷺ).