Sunan Abi Dawud 4317
سنن أبي داود#4317SahihShu’bah said in his version:“the letters k, f, r” (are on his forehead)
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Al-AlbaniSahih
Shuaib Al ArnautSahih
Zubair Ali ZaiSahih Muslim (2933)
In-book reference: 39:27