The Prophet ﷺ said, "When the first ten days of Dhul-Hijjah begin and one of you intends to offer a sacrifice, let him not touch anything of his hair or skin."In another wording, "Let him not take from his hair, nor clip a nail."
أن النبي ﷺ قال: إذا دخلت العشر، وأراد أحدكم أن يضحي، فلا يمس من شعره وبشره شيئا وفي لفظ: فلا يأخذن شعرا، ولا يقلمن ظفرا.
Muslim narrated it in the chapter on sacrifices (39:1977) from Ibn Abu Umar Makki, who said, Sufyan, that is Ibn Uyayna, narrated to us from Abdul-Rahman bin Humayd bin Abdul-Rahman bin Awf, who heard Saeed bin Musayab narrating from Umm Salama, and he mentioned it.The other wording is also found there from Ishaq bin Ibrahim, who said, Sufyan informed us of it. Sufyan was asked, "Some of them do not attribute it directly to the Prophet." He said, "But I attribute it directly to him."