Sahih al-Bukhari 3402
صحيح البخاري#3402SahihNarrated Abu Huraira:The Prophet (ﷺ) said, "Al-Khadir was named so because he sat over a barren white land, it turned green with plantation after (his sitting over it)
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: 60:75