﴿ فَبِأَىِّ حَدِيثٍۭ بَعْدَهُۥ يُؤْمِنُونَ ﴾

“In what other tiding, then, will they, after this, believe?”

In what discourse then after this namely the Qur’ān will they believe? In other words they cannot believe in any other of God’s Scriptures after having denied this Qur’ān since it comprises that inimitability i‘jāz which none of the others do.