Sunan an-Nasa'i 2363
سنن النسائي#2363SahihIt was narrated that 'Aishah said:"The Messenger of Allah used to be keen to fast on Mondays and Thursday
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 ZaiSahih
In-book reference: 22:274