Sunan an-Nasa'i 2366
سنن النسائي#2366HasanIt was narrated that Hafsah said:"The Messenger of Allah used to fast Thursday and Monday of each month, and Monday of the following week
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Abu GhuddahHasan
Al-AlbaniHasan
Zubair Ali ZaiIsnaad Hasan
In-book reference: 22:277