Narrated Aishah, Ummul Muminin: The Prophet ﷺ urinated and Umar was standing behind him with a jug of water. He said: What is this, Umar? He replied: Water for you to perform ablution with. He said: I have not been commanded to perform ablution every time I urinate. If I were to do so, it would become a sunnah.
Related hadith on this topic
Explanation & Benefits
Shaykh Umar Farooq Saeedi
Benefits and Issues:
This narration is weak in its chain of transmission; however, remaining in a state of ablution (wudu) at all times is a good deed, but it is not obligatory.
Source: Sunan Abu Dawood – Commentary by Shaykh Umar Farooq Saeedi, Page: 42