"The Messenger of Allah used to perform ablution for every prayer, and we used to perform all of the prayers with one ablution."
Sunan Ibn Majah Book 1, Hadith 243
← Previous Hadith The Prophet got up during the night and went to the toilet and relieved himself, then he washed his face and hands, and went back to sleep. (Sahih)

Another chain with similar wording.

Sunan Ibn Majah Book 1, Hadith 242 Next Hadith → The Prophet used to perform ablution for every prayer, but on the day of the conquest of Makkah, he performed all of the prayers with one ablution.

Sunan Ibn Majah Book 1, Hadith 244