Is it permissible to sell a quantity of a commodity by estimation (juzāf) for another estimated quantity of the same commodity?

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The sale of a quantity of one commodity by estimation (*juzāf*) for another quantity of the same commodity by estimation is impermissible. Scholars have reached a consensus that this is not permissible when both are of the same kind. This is supported by the Prophet's prohibition against selling an unmeasured heap (*ṣabrah*) of dates for a specified measure of dates. Furthermore, the command regarding exchanging gold for gold 'by weight for weight' implies that exchange must occur with exact equivalence. Equivalence (*tamāthul*) is a necessary condition, and ignorance of this equivalence invalidates the sale, similar to actual disproportionate exchange.