Sunan Ibn Majah 304
It was narrated that 'Abdullah bin Mughaffal said:
"The Messenger of Allah said: 'None of you should urinate in his wash area for most of the insinuating thoughts come from that.'" (Da'if)

Abu 'Abdullah bin Majah said: ("Abul-Hasan said: 'I heard Muhammed bin Yazid saying:) ''Ali bin Muhammed At-Tanafisi said: 'This (prohibition) applies to cases where the ground (in the place used for washing) was soft. But nowadays this does not apply, because the baths you use now are built of plaster, Saruj and tar; so if a person urinates there then pours water over it, that clears it away, and that is fine.'"
حَدَّثَنَا مُحَمَّدُ بْنُ يَحْيَى، حَدَّثَنَا عَبْدُ الرَّزَّاقِ، أَنْبَأَنَا مَعْمَرٌ، عَنْ أَشْعَثَ بْنِ عَبْدِ اللَّهِ، عَنِ الْحَسَنِ، عَنْ عَبْدِ اللَّهِ بْنِ مُغَفَّلٍ، قَالَ قَالَ رَسُولُ اللَّهِ ـ صلى الله عليه وسلم ـ ‏
"‏ لاَ يَبُولَنَّ أَحَدُكُمْ فِي مُسْتَحَمِّهِ فَإِنَّ عَامَّةَ الْوَسْوَاسِ مِنْهُ ‏"‏ ‏.‏
 قَالَ أَبُو عَبْدِ اللَّهِ بْنُ مَاجَهْ سَمِعْتُ عَلِيَّ بْنَ مُحَمَّدٍ الطَّنَافِسِيَّ يَقُولُ إِنَّمَا هَذَا فِي الْحَفِيرَةِ فَأَمَّا الْيَوْمَ فَلاَ ‏.‏ فَمُغْتَسَلاَتُهُمُ الْجَصُّ وَالصَّارُوجُ وَالْقِيرُ فَإِذَا بَالَ فَأَرْسَلَ عَلَيْهِ الْمَاءَ لاَ بَأْسَ بِهِ ‏.‏