Anas said:

"The Messenger of Allah sacrificed two horned, Amlah rams, saying: 'Allah Akbar and pronouncing the Name of Allah. I saw him slaughtering them with his own hand, and placing his foot on their sides." I said: You heard it from Him? He said: Yes. (Sahih )

أَخْبَرَنَا إِسْمَاعِيلُ بْنُ مَسْعُودٍ، قَالَ حَدَّثَنَا خَالِدٌ، عَنْ شُعْبَةَ، أَخْبَرَنِي قَتَادَةُ، قَالَ سَمِعْتُ أَنَسًا، قَالَ ضَحَّى رَسُولُ اللَّهِ صلى الله عليه وسلم بِكَبْشَيْنِ أَمْلَحَيْنِ أَقْرَنَيْنِ يُكَبِّرُ وَيُسَمِّي وَلَقَدْ رَأَيْتُهُ يَذْبَحُهُمَا بِيَدِهِ وَاضِعًا عَلَى صِفَاحِهِمَا قَدَمَهُ ‏.‏ قُلْتُ أَنْتَ سَمِعْتَهُ مِنْهُ قَالَ نَعَمْ ‏.‏