"Ibn Al-Musayyab told me that Umm Salamah, the wife of the Prophet told him that the Messenger of Allah said: 'Whoever wants to offer a sacrifice, let him not remove anything from his nails or cut his hair for the first ten days Dhul-Jijjah."' (Using translation from Nasāʾī 4362)   

عَنْ رَسُولِ اللَّهِ ﷺ أَنَّهُ قَالَ «مَنْ أَرَادَ أَنْ يُضَحِّيَ فَلَا يُقَلِّمْ أَظْفَارَهُ وَلَا يَحْلِقْ شَيْئًا مِنْ شَعْرِهِ فِي الْعَشْرِ الْأُوَلِ مِنْ ذِي الْحِجَّةِ»  

“When the ten days (of Dhul-Hijjah) begin, and one of you wants to offer a sacrifice, let him not remove anything from his hair or skin.” (Using translation from Ibn Mājah 3149)   

عَنِ النَّبِيِّ ﷺ قَالَ «إِذَا دَخَلَتِ الْعَشْرُ وَأَرَادَ أَحَدُكُمْ أَنْ يُضَحِّيَ فَلَا يَمَسَّ مِنْ شَعْرِهِ وَلَا أَظْفَارِهِ شَيْئًا»