The Book of Sacrifices (Kitab Al-Adahi)

Muslim :: Book 22 : Hadith 4869

Umm Salama reported Allah's Messenger (may peace be upon him) having said this: When any one of you intending to sacrifice the animal enters in the month (of Dhu'l-Hijja) he should not get his hair or nails touched (cut). It was said to Sufyan that some of the (scholars) did not deem this hadith to be Maffu'. He said: But I deem it as Marfu' (i. e. chain of narration traceable right up to the Holy Prophet).

Source materials are from the University of Southern California MSA site
Hadith eBooks converted from Imaan Star