Sahih (Sahih al-Bukhari)
وَعَنْ عُقْبَةَ بْنِ صُهْبَانَ، قَالَ سَمِعْتُ عَبْدَ اللَّهِ بْنَ الْمُغَفَّلِ الْمُزَنِيِّ، فِي الْبَوْلِ فِي الْمُغْتَسَلِ.
Abdullah bin Al-Mughaffal Al-Muzani also said:"The Prophet (ﷺ) also forbade urinating at the place where one takes a bath