Language:
كتاب الوضوء
4
Ablutions (Wudu')
(61)
Chapter: To urinate beside one's companion while screened by a wall
(61)
باب الْبَوْلِ عِنْدَ صَاحِبِهِ وَالتَّسَتُّرِ بِالْحَائِطِ

Narrated Hudhaifa':

The Prophet (ﷺ) and I walked till we reached the dumps of some people. He stood, as any one of you stands, behind a wall and urinated. I went away, but he beckoned me to come. So I approached him and stood near his back till he finished.

حَدَّثَنَا عُثْمَانُ بْنُ أَبِي شَيْبَةَ، قَالَ حَدَّثَنَا جَرِيرٌ، عَنْ مَنْصُورٍ، عَنْ أَبِي وَائِلٍ، عَنْ حُذَيْفَةَ، قَالَ رَأَيْتُنِي أَنَا وَالنَّبِيُّ، صلى الله عليه وسلم نَتَمَاشَى، فَأَتَى سُبَاطَةَ قَوْمٍ خَلْفَ حَائِطٍ، فَقَامَ كَمَا يَقُومُ أَحَدُكُمْ فَبَالَ، فَانْتَبَذْتُ مِنْهُ، فَأَشَارَ إِلَىَّ فَجِئْتُهُ، فَقُمْتُ عِنْدَ عَقِبِهِ حَتَّى فَرَغَ‏.‏
Reference : Sahih al-Bukhari 225
In-book reference : Book 4, Hadith 92
USC-MSA web (English) reference : Vol. 1, Book 4, Hadith 225
  (deprecated numbering scheme)