«اِلْقَبَّانِي شِرِيكِ الْمِحْتِسِبْ»

The proverb pictures the qabbani, who worked the public steelyard weighing goods, and the muhtasib, the traditional official supervising markets, weights, and trade conduct, as secret business partners. The inspector is not fooled; he lets tipped measurements slide because he takes a cut, so the safeguard meant to protect buyers becomes part of the swindle.

More broadly, it describes any overseer who colludes with the person under supervision, trading silence for a share of illicit profit. It warns that oversight means nothing when the monitor has a stake in the misconduct, and it mocks trust placed in such a compromised check.

Use when exposing an arrangement where the supposed watchdog shares in the gains of the party it should police, such as a regulator protecting a firm it profits from. It carries an accusatory, sardonic edge and suits criticism rather than neutral description.