Narrated Anas:
The Prophet ﷺ sacrificed two horned rams which were white with black markings, slaughtered, and uttered: "Allah is Most Great." and mentioned Allah's name and placed his foot on their sides.

حَدَّثَنَا مُسْلِمُ بْنُ إِبْرَاهِيمَ، حَدَّثَنَا هِشَامٌ، عَنْ قَتَادَةَ، عَنْ أَنَسٍ، أَنَّ النَّبِيَّ ﷺ ضَحَّى بِكَبْشَيْنِ أَقْرَنَيْنِ أَمْلَحَيْنِ يَذْبَحُ وَيُكَبِّرُ وَيُسَمِّي وَيَضَعُ رِجْلَهُ عَلَى صَفْحَتِهِمَا .