"The Messenger of Allah used to sacrifice two pronounce the name of Allah and say: 'Allah Akabar,' and I saw him slaughtering them with his own hand, and placing his foot on their sides "(Sahih )  

كَانَ رَسُولُ اللَّهِ ﷺ يُضَحِّي بِكَبْشَيْنِ أَمْلَحَيْنِ أَقْرَنَيْنِ وَكَانَ يُسَمِّي وَيُكَبِّرُ وَلَقَدْ رَأَيْتُهُ يَذْبَحُهُمَا بِيَدِهِ وَاضِعًا رِجْلَهُ عَلَى صِفَاحِهِمَا