It is reported about Sayyiduna Abu Sa'id al-Khudri (may Allah be pleased with him) that a man asked him about the ritual bath for janabah. He said: "Three (times)." The man said: "My hair is thick." Sayyiduna Abu Sa'id al-Khudri (may Allah be pleased with him) said: "The hair of the Prophet (peace and blessings be upon him) was thicker and purer."
Ahmad recorded it. Its chain contains a narrator, Atiyyah, whom Yahya bin Ma'in declared thiqah (trustworthy), while a group declared him da'if (weak), though a mild weakening.
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الطهارة / 1466