لَا تُسْرِفْ فِي الْمَاءِ وَإِنْ كُنْتَ عَلَى نَهْرٍ جَارٍ
Transliteration
La tusrif fi-l-ma'i wa in kunta 'ala naharin jar.
Translation
Do not waste water, even if you are at a flowing river.
Narrated by Abdullah ibn 'Amr·Sunan Ibn Majah 425 (attribution debated; commonly cited)
