"Whoever narrated to you that the Prophet would urinate while standing; then do not believe him. He would not urinate except while squatting." [He said:] There are narrations on this topic from Umar, Buraidah, [and Abdur-Rahman bin Hasanah].  

أَنَّ النَّبِيَّ ﷺ كَانَ يَبُولُ قَائِمًا فَلاَ تُصَدِّقُوهُ مَا كَانَ يَبُولُ إِلاَّ قَاعِدًا قَالَ وَفِي الْبَابِ عَنْ عُمَرَ وَبُرَيْدَةَ وَعَبْدِ الرَّحْمَنِ بْنِ حَسَنَةَ