The Book of Sacrifices
35/3. Chapter:
It is recommended to select a good animal for the sacrifice and to slaughter it oneself, not delegating it to anyone else, and to say the name of Allah, and to say the Takbir
Sahih Muslim
حَدَّثَنَا يَحْيَى بْنُ يَحْيَى، أَخْبَرَنَا وَكِيعٌ، عَنْ شُعْبَةَ، عَنْ قَتَادَةَ، عَنْ أَنَسٍ، قَالَ ضَحَّى رَسُولُ اللَّهِ صلى الله عليه وسلم بِكَبْشَيْنِ أَمْلَحَيْنِ أَقْرَنَيْنِ قَالَ وَرَأَيْتُهُ يَذْبَحُهُمَا بِيَدِهِ وَرَأَيْتُهُ وَاضِعًا قَدَمَهُ عَلَى صِفَاحِهِمَا قَالَ وَسَمَّى وَكَبَّرَ .
Anas reported that Allah's Messenger (ﷺ) sacrificed two horned rams of white colour with black markings over them. He also stated: I saw him sacrificing them with his own hand and saw him placing his foot on their sides, and recited the name of Allah and Glorified Him.
Reference : Sahih Muslim 1966bIn-book reference : Book 35, Hadith 25USC-MSA web (English) reference : Book 22, Hadith 4842