Surah An-Naml, ayah 71

27:71

وَيَقُولُونَ مَتَىٰ هَٰذَا ٱلۡوَعۡدُ إِن كُنتُمۡ صَٰدِقِينَ ٧١

Wayaqūlūna matā hādhal-wa'du in kuntum sādiqīn

And they say, "When is [the fulfillment of] this promise, if you should be truthful?"