Sunan an-Nasa'i 2406
سنن النسائي#2406SahihAbu Hurairah said:"The Messenger of Allah commanded me to pray two Rakahs of Duah,nt to sleep until after praying Witr and to fast three days of each month. (Sahih)
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: 22:317