Sahih Muslim 1324
Sahih Muslim · Book 15: The Book of Pilgrimage · It is permissible to ride the sacrificial animal if necessary
Abu Zubair reported:
وَحَدَّثَنِي سَلَمَةُ بْنُ شَبِيبٍ ، حَدَّثَنَا الْحَسَنُ بْنُ أَعْيَنَ ، حَدَّثَنَا مَعْقِلٌ ، عَنْ أَبِي الزُّبَيْرِ ، قَالَ سَأَلْتُ جَابِرًا عَنْ رُكُوبِ الْهَدْىِ، فَقَالَ سَمِعْتُ النَّبِيَّ صلى الله عليه وسلم يَقُولُ " ارْكَبْهَا بِالْمَعْرُوفِ حَتَّى تَجِدَ ظَهْرًا " .
I asked Jabir (Allah be pleased with him) about riding on the sacrificial animal, to which he replied: I heard Allah's Apostle (ﷺ) as saying: Ride on them gently until you find another mount.