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.

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