عَنْ نَافِعٍ قَالَ: رَأَيْتُ ابْنَ عُمَرَ يُصَلِّي عَلَى دَابَّتِهِ التَّطَوُّعَ حَيْثُ تَوَجَّهَتْ بِهِ، فَذَكَرْتُ لَهُ ذَلِكَ فَقَالَ: رَأَيْتُ أَبَا الْقَاسِمِ صَلَّى اللَّهُ عَلَيْهِ وَآلِهِ وَسَلَّمَ يَفْعَلُهُ
Nafi' says: I saw Sayyiduna Abdullah bin Umar (may Allah be pleased with him) performing voluntary prayers on his mount, whichever direction it turned. When I mentioned this to him, he said: I saw Abu al-Qasim (peace and blessings be upon him) doing the same.