Majma al-Zawaid — Hadith 14273

Sayyiduna Abu Asib (may Allah be pleased with him), or perhaps Sayyiduna Abu Asim (may Allah be pleased with him), narrates (the narrator Bahz says: he had the honour of attending the funeral prayer of the Prophet (peace and blessings be upon him)): The people said: "How shall we offer the funeral prayer for him?" He said: "Enter in groups." Then they would enter through this door, pray for mercy for him, and then go out through the other door. The narrator says: When the Prophet (peace and blessings be upon him) was placed in the lahd (niche of the grave), Sayyiduna Mughirah (may Allah be pleased with him) said: "Something has been left at his feet which they have not set right." The people said: "You go in and set it right." He went in, put his hand in, touched the feet of the Prophet (peace and blessings be upon him), and said: "Pour earth over it!" They poured earth there until it reached halfway up his shins. Then he came out and said: "Of all of you, my last meeting with the Prophet (peace and blessings be upon him) was the most recent."
Ahmad recorded it, and its narrators are the narrators of the "Sahih".