Sahih al-Bukhari 239
Book 4: Ablutions (Wudu') · Hadith 105
Hadith text
وَبِإِسْنَادِهِ قَالَ " لاَ يَبُولَنَّ أَحَدُكُمْ فِي الْمَاءِ الدَّائِمِ الَّذِي لاَ يَجْرِي، ثُمَّ يَغْتَسِلُ فِيهِ ".
The same narrator said that the Prophet (ﷺ) had said: "You should not pass urine in stagnant water which is not flowing then (you may need to) wash in it
Wahi rawi bataate hain ke Nabi ne farmaya: "Thehre hue (na behte) paani mein peshab na karo, kyunke phir tumhe usse ghusl karna pad sakta hai."
Sahih al-Bukhari 239 · Book 4, Hadith 105