The Prophet ﷺ as saying: If anyone has sacrificial animal and intends to sacrifice it, and he sights the new moon of Dhul-Hajjah, he must not take any of his hair and nails until he sacrifices Abu Dawud said: The name of 'Amr b. Muslim in the chain narrated by Malik and Muhammad b. 'Amr is disputed. Some say that it is 'Umar and the majority holds that it is 'Amr. Abu Dawud said: He is 'Amr b. Muslim b. Ukaimah al-Laithi al-Jundu'i.  

قَالَ رَسُولُ اللَّهِ ﷺ مَنْ كَانَ لَهُ ذِبْحٌ يَذْبَحُهُ فَإِذَا أَهَلَّ هِلاَلُ ذِي الْحِجَّةِ فَلاَ يَأْخُذَنَّ مِنْ شَعْرِهِ وَلاَ مِنْ أَظْفَارِهِ شَيْئًا حَتَّى يُضَحِّيَ