This excerpt is taken from Sheikh Farooq Rafi Sahib's book Qurbani, Aqiqah, and Ashra Zil-Hijjah.
The person who intends to perform Qurbani should not cut or trim hair and nails after sighting the moon of Dhu al-Hijjah until the Qurbani is performed. It is permissible and allowed to cut hair and trim nails after slaughtering the Qurbani. The evidences are as follows:
It is narrated from Sayyida Umm Salamah (may Allah be pleased with her) that the Prophet Muhammad (peace be upon him) said:
إذا دخلت العشر، وأراد أحدكم أن يضحي، فلا يمس من شعره و بشره شيئا
"When the tenth of Dhu al-Hijjah (i.e., when the moon of Dhu al-Hijjah appears) begins, and any one of you wants to perform Qurbani, he should not touch (i.e., cut) any part of his hair or skin (i.e., should not remove hair from any part of the body)."
Reference: Al-Mughni by Ibn Qudamah with Al-Sharh Al-Kabir: 11 / 97
