The Messenger of Allah ﷺ said: No one of you should make water in his bath and then wash himself there (after urination). The version of Ahmad has: Then performs ablution there, for evil thoughts come from it.
قَالَ رَسُولُ اللَّهِ ﷺ لاَ يَبُولَنَّ أَحَدُكُمْ فِي مُسْتَحَمِّهِ ثُمَّ يَغْتَسِلُ فِيهِ قَالَ أَحْمَدُ ثُمَّ يَتَوَضَّأُ فِيهِ فَإِنَّ عَامَّةَ الْوَسْوَاسِ مِنْهُ