Sunan an-Nasa'i, Volume 5, Book 43, Hadith 4392 (DarusSalam) ⓘ
It was narrated that Anas said: "The Prophet sacrificed two horned, Amlah rams, slaughtering them with his own hand, pronouncing the name of Allah, and saying: 'Allahu Akbar, and placing his foot on their sides."
أَخْبَرَنَا قُتَيْبَةُ، قَالَ حَدَّثَنَا أَبُو عَوَانَةَ، عَنْ قَتَادَةَ، عَنْ أَنَسٍ، قَالَ ضَحَّى النَّبِيُّ صلى الله عليه وسلم بِكَبْشَيْنِ أَمْلَحَيْنِ أَقْرَنَيْنِ ذَبَحَهُمَا بِيَدِهِ وَسَمَّى وَكَبَّرَ وَوَضَعَ رِجْلَهُ عَلَى صِفَاحِهِمَا .
also referenced under: Hadith 4387 (Reference) & Book 43, Hadith 27 (In-Book)