Sayyiduna Hudhayfah (may Allah be pleased with him) narrates that I saw myself walking with the Messenger of Allah (peace and blessings be upon him). When he reached the people's refuse heap (a pile of garbage and filth), he stood and began to urinate, just as any one of you urinates. I started to move away from him, but the Messenger of Allah (peace and blessings be upon him) said: "Come closer." So I came closer to him until I was standing behind him (and remained standing) until the Messenger of Allah (peace and blessings be upon him) finished (urinating).
Hadith Referenceصحيح ابن خزيمه / جماع أبواب الآداب المحتاج إليها في إتيان الغائط والبول إلى الفراغ منها / 52
Hadith Takhrij«أحمد: 382/5 ، 402 ، من طريق منصور عن أبى وائل ، صحيح بخاري: كتاب الوضوء ، باب البول عند صاحبه والتستر بالحائط ، رقم الحديث: 225 ، 2471 ، صحيح مسلم: 273»