قُلْ يَـٰٓأَيُّهَا ٱلْكَـٰفِرُونَ
Qul yaa-ai yuhal kaafiroon
Say [Prophet], ‘Disbelievers:
Say: you who deny the truth,
Only here are deniers addressed by the noun, al-kāfirūn, as a standing description. The one other place that vocative is used of them is 66:7, where the wording shifts to those who denied, a verb naming what they did, and where it is spoken on the day of judgment. The line is also a script, opened with say, so what follows is meant to be said aloud rather than merely held.