Sunan an-Nasa'i 2369
سنن النسائي#2369SahihIt was narrated that Abu Hurairah said:"The Messenger of Allah commanded me to pray two Rakahs of Duha, and not to sleep until I had prayed witr, and to fast three days each month
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: 22:280