Sahih al-Bukhari 5564
Sahih al-Bukhari · Book 73: Al-Adha Festival Sacrifice (Adaahi) · To put one's foot on the side of the animal at the time of slaughtering
Narrated Anas:
حَدَّثَنَا حَجَّاجُ بْنُ مِنْهَالٍ ، حَدَّثَنَا هَمَّامٌ ، عَنْ قَتَادَةَ ، حَدَّثَنَا أَنَسٌ ـ رضى الله عنه ـ أَنَّ النَّبِيَّ صلى الله عليه وسلم كَانَ يُضَحِّي بِكَبْشَيْنِ أَمْلَحَيْنِ أَقْرَنَيْنِ، وَوَضَعَ رِجْلَهُ عَلَى صَفْحَتِهِمَا، وَيَذْبَحُهُمَا بِيَدِهِ .
The Prophet (ﷺ) used to offer as sacrifices, two horned rams, black and white in color, and used to put his foot on their sides and slaughter them with his own hands.