Amir (al-Sha'bi) (may Allah have mercy on him) says that the Messenger of Allah (peace and blessings be upon him) was given the ritual bath (ghusl) by Sayyiduna Ali, Sayyiduna al-Fadl and Sayyiduna Usamah bin Zayd (may Allah be pleased with them), and it was they who placed him in the grave. He said: Marhab or Ibn Abi Marhab narrated to me that Sayyiduna Abd al-Rahman bin Awf (may Allah be pleased with him) was also with them when they lowered him into the grave. When they had finished burying him, Sayyiduna Ali (may Allah be pleased with him) said: Those closest to a man are his own family.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الجنائز / 7041