´It was narrated from Umm Salamah that the Messenger of Allah said:` "when the (first) ten (days of Dhul-Jijjah) begin, and one of you wants to offer a sacrifice, let him not remove anything from his hair or skin."
Hadith ReferenceSunan an-Nasa'i / The Book of ad-Dahaya (Sacrifices) / Hadith: 4369