Sunan an-Nasa'i 142
سنن النسائي#142SahihIt was narrated that 'Abdullah bin 'Amr said:"The Messenger of Allah (ﷺ) said: 'Do Wudu' properly.'" [1] [1] Isbighu Al-Wudu'. And this narration supports the claim that some of them used this expression to mean "three times" for each limb, rather than "properly
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Abu GhuddahSahih
Al-AlbaniSahih
Zubair Ali ZaiHasan
In-book reference: 1:143