Sunan Ibn Majah 509
سنن ابن ماجه#509SahihIt was narrated that Anas bin Malik said:"The Messenger of Allah used to perform ablution for every prayer, and we used to perform all of the prayers with one ablution
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Al-AlbaniSahih
Muhammad Fouad Abd al-BaqiSahih
Zubair Ali ZaiSahih Bukhari
In-book reference: 1:243