حبل الكذب قصير (ḥabl al-kadhib qaṣīr)

Literally: The rope of lies is short

Example: “ادّعى أنه مريض، لكن صوره في الشاطئ ظهرت؛ حبل الكذب قصير.” — He claimed he was sick, but his beach photos turned up; the truth will out.

Origin: "The rope of lies is short": a lie, like a short rope, cannot reach far before it runs out. The proverb is common across the Arab world, and other languages have the same idea in different pictures, such as German Lügen haben kurze Beine (lies have short legs). No first use is documented.