«دَا حِلْمْ وَالَّا عِلْمْ؟»

An exclamation of astonishment. Faced with something hard to credit, the speaker asks whether the moment belongs to sleep or to waking life. Here ʿilm means being awake and in touch with what is real, not learning or scholarship, signalling that what happened seemed too improbable to be real.

It answers an event nobody was counting on, or the appearance of a person whom one had no hope of meeting. The question is rhetorical: it voices amazement, not sincere doubt about one's own state of mind, nor a claim that the event is untrue.

Exclaim it when someone you had given up on seeing suddenly arrives, or when something you never expected to happen takes place. It suits a lively greeting to the surprising visitor as well as a reaction to unlooked-for news.