«اِللِّي نْبَاتْ فِيهْ نِصْبَحْ فِيهْ»

In this dialectal Arabic saying, the night-and-morning image is figurative: a person remains absorbed in one matter from evening until morning. It conveys attention that does not shift, rather than literal sleeping arrangements.

It can also describe someone who repeatedly brings up the same topic in conversation. The image stresses persistence, presenting the subject as a constant companion rather than a passing thought.

Use it for someone occupied with the same thing at all hours, or who keeps returning to one subject in speech. It remarks on the persistence of that focus, not on the particular subject, and should be understood figuratively rather than as a literal reference to sleep.