This hadeeth comes under the following chapter: IT IS MERITORIOUS TO SACRIFICE THE ANIMAL WITH ONE'S OWN HAND AND SO IS MERITORIOUS THE RECITATION OF BISMILLAH (IN THE NAME OF ALLAAH) AND TAKBIR (ALLAAH-O-AKBAR)
Anas reported that Allaah's Messenger (sallAllaahu alayhi wa sallam) sacrificed with his own hands two horned rams which were white with black markings reciting the name of Allaah and glorifying Him (saying Allaah-o-Akbar). He placed his foot on their sides (while sacrificing).