أَخْبَرَنَا عَلِيُّ بْنُ حُجْرٍ، قَالَ أَنْبَأَنَا ابْنُ الْمُبَارَكِ، عَنْ مَعْمَرٍ، عَنِ الأَشْعَثِ بْنِ عَبْدِ اللَّهِ، عَنِ الْحَسَنِ، عَنْ عَبْدِ اللَّهِ بْنِ مُغَفَّلٍ، عَنِ النَّبِيِّ صلى الله عليه وسلم قَالَ " لاَ يَبُولَنَّ أَحَدُكُمْ فِي مُسْتَحَمِّهِ فَإِنَّ عَامَّةَ الْوَسْوَاسِ مِنْهُ " .
It was narrated from 'Abdullah bin Mughaffal that the Prophet (PBUH) said: "None of you should urinate in the place where he bathes, for most Waswas (devilish whispers) [1] come from that." [1] I.e., with regard to whether the urine has soiled his body or not. Translation Not Available
Book Ref: Sunan An Nisai Book 1 Hadith 36
Web Ref: Sunan An Nisai Vol 1 Book 1 Hadith 36