To slaughter the camels while they are standing

Narrated Anas :

The Prophet offered four Rakat of Zuhr prayer at Medina;
and two Rakat of 'Asr prayer at Dhul-hulaifa and spent the night there and when (the day) dawned, he mounted his Mount and started saying, "None has the right to be worshipped but Allah, and Glorified be Allah." When he reached Al-Baida' he recited Talbiya for both Hajj and 'Umra. And when he arrived at Mecca, he ordered them (his companions) to finish their Ihram. The Prophet slaughtered seven Budn (camel) with his own hands while the camels were standing He also sacrificed two horned rams (black and white in color) at Medina.

حَدَّثَنَا سَهْلُ بْنُ بَكَّارٍ، حَدَّثَنَا وُهَيْبٌ، عَنْ أَيُّوبَ، عَنْ أَبِي قِلاَبَةَ، عَنْ أَنَسٍ ـ رضى الله عنه ـ قَالَ صَلَّى النَّبِيُّ ﷺ الظُّهْرَ بِالْمَدِينَةِ أَرْبَعًا، وَالْعَصْرَ بِذِي الْحُلَيْفَةِ رَكْعَتَيْنِ، فَبَاتَ بِهَا، فَلَمَّا أَصْبَحَ رَكِبَ رَاحِلَتَهُ، فَجَعَلَ يُهَلِّلُ وَيُسَبِّحُ، فَلَمَّا عَلاَ عَلَى الْبَيْدَاءِ لَبَّى بِهِمَا جَمِيعًا، فَلَمَّا دَخَلَ مَكَّةَ أَمَرَهُمْ أَنْ يَحِلُّوا. وَنَحَرَ النَّبِيُّ ﷺ بِيَدِهِ سَبْعَ بُدْنٍ قِيَامًا، وَضَحَّى بِالْمَدِينَةِ كَبْشَيْنِ أَمْلَحَيْنِ أَقْرَنَيْنِ.