Sunan an-Nasa'i 2187
سنن النسائي#2187SahihIt was narrated that 'Aishah said:"The Messenger of Allah used to fast Sha`ban and Ramadan, and he made sure 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 ZaiIsnaad Sahih
In-book reference: 22:98