Sahih al-Bukhari 5558Book 73, Hadith 14
حَدَّثَنَا آدَمُ بْنُ أَبِي إِيَاسٍ، حَدَّثَنَا شُعْبَةُ، حَدَّثَنَا قَتَادَةُ، عَنْ أَنَسٍ، قَالَ ضَحَّى النَّبِيُّ صلى الله عليه وسلم بِكَبْشَيْنِ أَمْلَحَيْنِ، فَرَأَيْتُهُ وَاضِعًا قَدَمَهُ عَلَى صِفَاحِهِمَا يُسَمِّي وَيُكَبِّرُ، فَذَبَحَهُمَا بِيَدِهِ.
The Prophet (ﷺ) slaughtered two rams, black and white in color (as sacrifices), and I saw him putting his foot on their sides and mentioning Allah's Name and Takbir (Allahu Akbar). Then he slaughtered them with his own hands.