«عُمْرِ الْغَابْ مَا يْصَح مِنُّه اوْتَادْ»

The saying holds that some things are simply the wrong stuff for a given job. Here الغاب means reed or cane, not forest, and the opening عُمْر means 'never': a hollow, flimsy reed will never become a sturdy peg, because it cannot bear the strain a stake must withstand.

Applied more widely, it warns against expecting strength, reliability, or endurance from someone or something whose basic nature cannot supply it. The fault lies in the material, not in the effort, so persisting only wastes time.

Use it when someone keeps trying to force a person, tool, or material into a role it cannot bear, or to explain an expected failure. It can sound dismissive when applied to people, so take care when the target is present.