Sunan Ibn Majah 941
It was
narrated that Ibn ‘Umar said:
“A small spear (Harbah) would be
brought out to the Prophet (ﷺ) when he was travelling; he would
plant it (in the ground) to perform prayer while facing it.”
حَدَّثَنَا مُحَمَّدُ بْنُ الصَّبَّاحِ، أَنْبَأَنَا عَبْدُ اللَّهِ بْنُ رَجَاءٍ الْمَكِّيُّ، عَنْ عُبَيْدِ اللَّهِ، عَنْ نَافِعٍ، عَنِ ابْنِ عُمَرَ، قَالَ كَانَ النَّبِيُّ ـ صلى الله عليه وسلم ـ تُخْرَجُ لَهُ حَرْبَةٌ فِي السَّفَرِ، فَيَنْصِبُهَا فَيُصَلِّي إِلَيْهَا ‏.‏