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
وَحَدَّثَنَا يَحْيَى بْنُ حَبِيبٍ، حَدَّثَنَا خَالِدٌ، - يَعْنِي ابْنَ الْحَارِثِ - حَدَّثَنَا شُعْبَةُ، أَخْبَرَنِي قَتَادَةُ، قَالَ سَمِعْتُ أَنَسًا، يَقُولُ ضَحَّى رَسُولُ اللَّهِ صلى الله عليه وسلم . بِمِثْلِهِ . قَالَ قُلْتُ آنْتَ سَمِعْتَهُ مِنْ أَنَسٍ قَالَ نَعَمْ .
Shu'ba reported: Qatada informed me that he had heard Anas saying that Allah's Messenger (may peace be npon him) sacrificed (the horned rams) and like that. I said: Did you (Qatada) hear from Anas? He said. Yes.
Reference : Sahih Muslim 1966cIn-book reference : Book 35, Hadith 26USC-MSA web (English) reference : Book 22, Hadith 4843