Sahih Muslim 1966 b
Anas reported that Allah's Messenger (ﷺ) sacrificed two horned rams of white colour with black markings over them. He also stated:
I saw him sacrificing them with his own hand and saw him placing his foot on their sides, and recited the name of Allah and Glorified Him.
حَدَّثَنَا يَحْيَى بْنُ يَحْيَى، أَخْبَرَنَا وَكِيعٌ، عَنْ شُعْبَةَ، عَنْ قَتَادَةَ، عَنْ أَنَسٍ، قَالَ ضَحَّى
 رَسُولُ اللَّهِ صلى الله عليه وسلم بِكَبْشَيْنِ أَمْلَحَيْنِ أَقْرَنَيْنِ قَالَ وَرَأَيْتُهُ يَذْبَحُهُمَا بِيَدِهِ وَرَأَيْتُهُ
 وَاضِعًا قَدَمَهُ عَلَى صِفَاحِهِمَا قَالَ وَسَمَّى وَكَبَّرَ ‏.‏