It wasnarrated from Anas bin Malik:
"The Messenger of Allah (ﷺ)used tosacrifice two horned, black-and-white rams and he would saythe Nameof Allah and pronounce His greatness. I saw him slaughteringthemwith his own hand, putting his foot on their sides." (ES)
English reference (ES): Vol. 4, Book 26, Hadith 3120 (ES)
Arabic reference (ES): Book 26, Hadith 3239 (ES)