It was narrated from Anas bin Malik:
“The Messenger of Allah ﷺ used to sacrifice two horned, black-and-white rams and he would say the Name of Allah and pronounce His greatness. I saw him slaughtering them with his own hand, putting his foot on their sides.”

حَدَّثَنَا نَصْرُ بْنُ عَلِيٍّ الْجَهْضَمِيُّ، حَدَّثَنِي أَبِي ح، وَحَدَّثَنَا مُحَمَّدُ بْنُ بَشَّارٍ، حَدَّثَنَا مُحَمَّدُ بْنُ جَعْفَرٍ، قَالاَ حَدَّثَنَا شُعْبَةُ، سَمِعْتُ قَتَادَةَ، يُحَدِّثُ عَنْ أَنَسِ بْنِ مَالِكٍ، أَنَّ رَسُولَ اللَّهِ ﷺ كَانَ يُضَحِّي بِكَبْشَيْنِ أَمْلَحَيْنِ أَقْرَنَيْنِ وَيُسَمِّي وَيُكَبِّرُ وَلَقَدْ رَأَيْتُهُ يَذْبَحُ بِيَدِهِ وَاضِعًا قَدَمَهُ عَلَى صِفَاحِهِمَا .