Prophetic Commentary on the Qur'an (Tafseer of the Prophet (pbuh))
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
From Sahih al-Bukhari, whose reports the scholars accept as authentic.