Surah As-Saffat, ayah 19

فَإِنَّمَا هِيَ زَجۡرَةٞ وَٰحِدَةٞ فَإِذَا هُمۡ يَنظُرُونَ ١٩

Fa innamā hiya zajratun wāhidatun fa idhā hum yanzurūn

It will be only one shout, and at once they will be observing.