It is narrated from Sayyiduna Mughirah bin Shu'bah (may Allah be pleased with him); he said: "I was among those who dug the grave of the Prophet (peace and blessings be upon him)." He said: "We made a lahd (niche) for him (peace and blessings be upon him). Then, when the Prophet (peace and blessings be upon him) was lowered into the grave, I dropped the axe, then said: 'The axe, the axe (hand it to me),' and so I went down (into the grave) and placed my hand on the lahd." And Mughirah (may Allah be pleased with him) used to say: "I am the closest of people in terms of (the last) time spent with the Messenger of Allah (peace and blessings be upon him)."
Hadith Referenceالمعجم الكبير للطبراني / باب الميم / 18117