Hadith on Water: Conserve water even if you are on the banks of a running stream

Abdullah ibn Amr reported: The Messenger of Allah, peace and blessings be upon him, passed by Sa’d while he was performing ablution. The Prophet said, “What is this extravagance?” Sa’d said, “Is there extravagance with water in ablution?” The Prophet said, “Yes, even if you were on the banks of a flowing river.”

Source: Sunan Ibn Mājah 425

Grade: Sahih (authentic) according to Ahmad Shakir