Sahih al-Bukhari 136
صحيح البخاري#136SahihNarrated Nu`am Al-Mujmir:Once I went up the roof of the mosque, along with Abu Huraira. He performed ablution and said, "I heard the Prophet (ﷺ) saying, "On the Day of Resurrection, my followers will be called "Al-Ghurr-ul- Muhajjalun" from the trace of ablution and whoever can increase the area of his radiance should do so (i.e. by performing ablution regularly)
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Every narration in Sahih al-Bukhari is accepted as Sahih (authentic) by the established status of the book.
In-book reference: 4:2