Sunan an-Nasa'i 613
سنن النسائي#613SahihIt was narrated that Anas said:The Messenger of Allah (ﷺ) said: "Whoever forgets a prayer, let him pray it when he remembers it
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 - Agreed Upon
In-book reference: 6:120