It was narrated from Abu Hurairah that the Messenger of Allah ﷺ forbade urinating into standing water and then performing Ghusl from Janabah in it.
أَنَّ رَسُولَ اللَّهِ ﷺ نَهَى أَنْ يُبَالَ فِي الْمَاءِ الدَّائِمِ ثُمَّ يُغْتَسَلَ فِيهِ مِنَ الْجَنَابَةِ