Surah 52. At-Tur, Ayah 31

I.e., "Whereas you are waiting for my message to be proved false, I am awaiting its fulfilment!"

Cf. ix. 52. If the wicked wait or look for some calamity to befall the Prophet, the Prophet can with far more justice await the decision of the issue between him and his persecutors. For he stands for right, and Allah will support the right.