Sunan an-Nasa'i 779
سنن النسائي#779SahihIt was narrated that 'Abdullih said:"The Messenger of Allah (ﷺ) said: 'You may live to meet people who will be offering the prayer outside its (prayer) time. If you meet them, then offer the prayer on time, then pray with them and make that a voluntary prayer
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Abu GhuddahHasan Sahih
Al-AlbaniHasan Sahih
Zubair Ali ZaiSahih
In-book reference: 10:3