«إذا دخل العشر وأراد أحدكم أن يضحي فلا يمس من شعره ولا من بشره شيئا»
The Prophet (peace and blessings be upon him) said:
"When the (first) ten days (of Dhul-Hijjah) begin and any of you intends to offer a sacrifice, he should not cut anything from his hair or his body (such as nails or skin)."
Hadith Referenceصحیح الجامع الصغیر / حرف الألف / 520