Shu’bah said in his version: “the letters k, f, r” (are on his forehead).
حَدَّثَنَا مُحَمَّدُ بْنُ الْمُثَنَّى، عَنْ مُحَمَّدِ بْنِ جَعْفَرٍ، عَنْ شُعْبَةَ، ك ف ر .