صَحِيحُ مُسْلِمٍ
Sahih Muslim 1966 a
The Book of Sacrifices
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
حَدَّثَنَا قُتَيْبَةُ بْنُ سَعِيدٍ، حَدَّثَنَا أَبُو عَوَانَةَ، عَنْ قَتَادَةَ، عَنْ أَنَسٍ، قَالَ ضَحَّى النَّبِيُّ صلى الله عليه وسلم بِكَبْشَيْنِ أَمْلَحَيْنِ أَقْرَنَيْنِ ذَبَحَهُمَا بِيَدِهِ وَسَمَّى وَكَبَّرَ وَوَضَعَ رِجْلَهُ عَلَى صِفَاحِهِمَا .
Anas reported that Allah's Messenger (ﷺ) sacrificed with his own hands two horned rams which were white with black markings reciting the name of Allah and glorifying Him (saying Allah-o-Akbar). He placed his foot on their sides (while sacrificing).
Sahih Muslim, 1966 aSahihصحيح