Riyad as-Salihin · Chapter 313

Prohibition of having a Hair cut or paring one's nail during the first ten days of Dhul-Hijjah for one who intends to Sacrifice an Animal

باب نهي من دخل عليه عشر ذي الحجة وأراد أن يضحي عن أخذ شيء من شعره أو أظفاره حتى يضحي

This chapter speaks to anyone who plans to offer a sacrificial animal and finds the first ten days of Dhul-Hijjah arriving. The single hadith here gives a clear instruction: such a person should leave their hair and nails untouched until the sacrifice has been made.

Read it as a small act of mindfulness that ties the believer to the coming sacrifice, marking these days as set apart. The wider details of how this is understood belong to the scholars; what concerns the reader is the simple spirit of preparing the heart for an act of worship.

Hadith 1706

Umm Salamah (May Allah be pleased with her) said:

عن أم سلمة رضي الله عنها قالت قال رسول الله صلى الله عليه وسلم ‏:‏ ‏ "‏من كان له ذبح يذبحه، فإذا أهل هلال ذي الحجة، فلا يأخذن من شعره ولا من أظفاره شيئًا حتى يضحي‏" ‏ ‏(‏‏(‏رواه مسلم‏)‏‏)‏‏.‏

The Messenger of Allah (ﷺ) said, "When anyone of you intends to sacrifice the animal and enter in the month of Dhul-Hijjah, he should not get his hair cut or nails pared till he has offered his sacrifice." [Muslim].

In plain words

Whoever intends to offer a sacrifice, once the month of Dhul-Hijjah has begun, is told not to cut his hair or trim his nails until the sacrifice is made. A small way of marking these days for worship.

Reference : Riyad as-Salihin 1706 In-book reference : Book 17, Hadith 196