وَعَن ابنِ عمَرَ: أَنَّهُ أَتَى عَلَى رَجُلٍ قَدْ أَنَاخَ بِدَنَتَهُ يَنْحَرُهَا قَالَ: ابْعَثْهَا قِيَامًا مُقَيَّدَةً سُنَّةَ مُحَمَّدٍ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ
Ibn ‘Umar came upon a man who had made his camel kneel and was sacrificing it, so he told him to make it stand up fettered according to the sunna of Muhammad. Bukhari and Muslim.