Sunan an-Nasa'i 2418
سنن النسائي#2418SahihIt was narrated from Hunaidah bin Khalid, from his wife, that one of the wives of the Prophet said:"The Prophet used to fast the ten (days), and three days of each month: Monday 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 ZaiHasan
In-book reference: 22:329