Sunan an Nasai 4416
The Book of ad-Dahaya (Sacrifices)
أَخْبَرَنَا أَحْمَدُ بْنُ نَاصِحٍ، قَالَ حَدَّثَنَا هُشَيْمٌ، عَنْ شُعْبَةَ، عَنْ قَتَادَةَ، قَالَ حَدَّثَنَا أَنَسُ بْنُ مَالِكٍ، قَالَ كَانَ رَسُولُ اللَّهِ صلى الله عليه وسلم يُضَحِّي بِكَبْشَيْنِ أَمْلَحَيْنِ أَقْرَنَيْنِ وَكَانَ يُسَمِّي وَيُكَبِّرُ وَلَقَدْ رَأَيْتُهُ يَذْبَحُهُمَا بِيَدِهِ وَاضِعًا رِجْلَهُ عَلَى صِفَاحِهِمَا .
Anas bin Malik said:"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)
Grading: Abu Ghuddah: Sahih · Al-Albani: Sahih · Zubair Ali Zai: Hasan
Text from the public-domain hadith-api dataset. Numbering follows that dataset and can differ by a few from some printed editions — check the wording, not only the number.