Umar bin Muslim narrates: Some time before Eid al-Adha, we were in the bathhouse. There, some people were preparing to remove hair, so a person present in the bathhouse said: Sa'id bin al-Musayyib has considered this disliked and he forbids it. The narrator says: I met Sa'id bin al-Musayyib and mentioned this matter to him, so he said: O my nephew, this hadith has been forgotten. Lady Umm Salamah (may Allah be pleased with her) has informed me of this: The Prophet Muhammad (peace and blessings be upon him) said: "When the (first) ten days (of Dhul-Hijjah) begin and any one of you has an animal for sacrifice which he intends to offer, then he should not cut his hair or nails until he has offered the sacrifice."