Answered by Mufti Mohammed Tosir Miah
Who should refrain from cutting the hairs and nails from the month of Zul Hijjah?
Saaidah Umm Salamah narrates that the Prophet of Allah said, “When one of you sees the moon of Zul Hijjah and whoever among you wants to offer a sacrifice, let him not take anything from his hair or nails.” (Sahih Muslim, Sunan Ab Dawud & Sunan Tirmizi)
According to Imam Abu Hanifa the aforementioned ruling is mustuhub (desirable) where as other scholars such as Imam Ahmad says it is obligatory to refrain from cutting ones hair and nails. (Taqrir Tirmizi p.173 v.2)
The above ruling applies to the one who is offering the sacrifice, and does not extend to those upon whom sacrifice is not obligatory.
Only Allah Knows Best
Mohammed Tosir Miah
Darul Ifta Birmingham