Surah 37. As-Saffat, Ayah 177

Lit., "when it alights in their courtyard, evil [or "hapless"] is the morning of those...", etc. In ancient Arabic usage, the idiomatic phrase "chastisement [or "suffering"] has alighted (nazala) in so-and-so's courtyard" denotes its coming-down upon, or befalling, the person or persons concerned (Tabari). Similarly, the "morning" (sabah) is a metonym for "awakening".

 lit., when it lands in their courtyards.

See last note. The parable is that of an enemy camp in a plain, which is surprised and destroyed by a night attack from the hills. Evil is the plight of any survivors in the morning. Their regrets will be all the more poignant if they had had some sort of a warning before hand and had paid no heed to it!