Musnad Ahmad 30:3255

Muhammad ibn Ja‘far and Rawh narrated to us, they said: ‘Awf narrated to us, from Muhammad ibn Sirin, he said—and Rawh said: and Khilas—from Abu Hurayrah, that the Messenger of Allah (peace and blessings of Allah be upon him) forbade that one should urinate in stagnant water, then perform ablution from it. And Rawh said: "Let not one of you urinate [in it]."