The supererogatory prayer differs from the obligatory prayer with regards to some of its rulings, and some of which have been mentioned in this hadeeth. ʿAbdullah ibn ʿUmar (may Allah be pleased with them) narrates that the Prophet ﷺ would pray supererogatory prayers during the journey while he was riding atop his mount that he disembarked with in any direction that he proceeded towards. However, he would first perform the opening takbir while facing the Qiblah, and then his mount would move in any direction after that. He ﷺ used to motion by gesturing, [and this was done] by moving his head to serve as an indication for the movements of bowing and prostration; and the nodding motions for the prostration were lower than the gestures for bowing. He ﷺ would do this for the supererogatory prayers, including the Witr prayer. As for the obligatory prayers, he ﷺ would not do this while traveling. But rather, he used to dismount from his riding animal and perform the obligatory prayer on the ground, facing the Qiblah. This was to facilitate and alleviate in matter[s] of supererogatory and voluntary prayers. As for that which is obligatory, one may not pray while he is on his mount - other than out of an excuse pertaining to an intense fear or sickness, and the like..