These readings are verbal nouns based on forms II and I, respectively. The first is a more intensive form, or has the sense of rejection of truth [al-Razi].
He has revealed to you ˹O Prophet˺ the Book in truth, confirming what came before it, as He revealed the Torah and the Gospel
Explanation
These readings are verbal nouns based on forms II and I, respectively. The first is a more intensive form, or has the sense of rejection of truth [al-Razi].