«زُبُونِ الْعَتْمَهْ فُلُوسُهْ زَغَلْ»

The image is of a habitual customer of a particular shop who deliberately comes to buy after nightfall, because a merchant in the darkness cannot easily examine coins. Whatever he hands over is likely to be counterfeit, since the darkness itself is the reason he chose that moment.

More broadly, the saying targets people who pick their timing to exploit others, waiting for circumstances that hide their fraud. It points to opportunism as the warning sign: when someone favors conditions that prevent scrutiny, their dealings deserve suspicion.

Use it to call out someone who waits for confusion, haste, or poor visibility before cheating, or to warn a trader to inspect payment carefully when conditions favor deception. It works as a sharp remark about calculated dishonesty rather than simple carelessness.