"Water is not made impure by anything." [1] [1] See the following versions. (Using translation from Nasāʾī 325)  

أَنَّ بَعْضَ أَزْوَاجِ النَّبِيِّ ﷺ اغْتَسَلَتْ مِنَ الجَنَابَةِ فَتَوَضَّأَ النَّبِيُّ ﷺ بِفَضْلِهِ فَذَكَرَتْ ذَلِكَ لَهُ فَقَالَ إِنَّ الْمَاءَ لَا يُنَجِّسُهُ شَيْءٌ  

[Machine] "A woman from the wives of the Prophet ﷺ performed ghusl from janabah (post-sexual impurity). Then the Prophet ﷺ came and performed wudu from the leftover water. She said to him, and he said, 'Verily, nothing makes the water impure.'"  

أَنَّ امْرَأَةً مِنْ أَزْوَاجِ النَّبِيِّ ﷺ اغْتَسَلَتْ مِنْ جَنَابَةٍ فَجَاءَ النَّبِيُّ ﷺ يَتَوَضَّأُ مِنْ فَضْلِهَا فَقَالَتْ لَهُ فَقَالَ «إِنَّ الْمَاءَ لَا يُنَجِّسُهُ شَيْءٌ»  

One of the wives of the Prophet ﷺ took a bath from a large bowl. The Prophet ﷺ wanted to perform ablution or take from the water left over. She said to him: O Prophet of Allah, verily I was sexually defiled. The Prophet said: Water not defiled. (Using translation from Abū Dāʾūd 68)   

اغْتَسَلَ بَعْضُ أَزْوَاجِ النَّبِيِّ ﷺ فِي جَفْنَةٍ فَجَاءَ النَّبِيُّ ﷺ يَتَوَضَّأُ أَوْ يَغْتَسِلُ مِنْ فَضْلِهَا فَقَالَتْ يَا رَسُولَ اللَّهِ إِنِّي كُنْتُ جُنُبًا فَقَالَ رَسُولُ اللَّهِ ﷺ «إِنَّ الْمَاءَ لَا يُنَجِّسُهُ شَيْءٌ»