Sahih Bukhari
Al-Adha Festival Sacrifice (Adaahi)
Volume: 007 / Book Number: 068 / Hadith Number: 465
Narrated Anas:
The Prophet slaughtered two rams, black and white in color (as sacrifices), and I saw him putting his foot on their sides and mentioning Allah's Name and Takbir (Allahu Akbar). Then he slaughtered them with his own hands.