Chapter on Juʿāla (Contingent Rewards)
The stipulated reward must not be unknown or involve gharar; it is valid only when it is clearly defined and understood. If a person’s slave absconds and he says, “Whoever brings him back to me shall have half of him,” this arrangement is invalid, because at that moment it is unlawful to sell half the slave. Should someone nonetheless bring the slave back, he is entitled to the customary fee for such work. And whoever promises a reward in connection with a slave—