Tafsir of Ya seen 36:3

This is the response to the oath, and the sentence serves to refute the disbelievers' denial of his messengership—peace and blessings be upon him—for they had said: "You are not a messenger." It has already been noted that they were at an extreme degree of denial, as indicated by the words of the Almighty: "But when a warner came to them, it did not increase them except in aversion," due to their arrogance in the land and their evil plotting. This verse is among those referred to by the Almighty’s statement in response to their denial: "Say, 'Sufficient is Allah as Witness between me and you.'"

Singling out the Quran by swearing by it first, and by describing it as "the Wise" second, is an exaltation of its status in the most perfect manner.