Muwatta Imam Malik (Riwayat Yahya)

Imam Malik, may Allah have mercy on him, said that if a person buys several slaves at the same time (i.e., in a single contract), and among them one slave turns out to be a thief or has some defect, then if that slave is the best and most distinguished among all the slaves and the rest of the slaves were bought because of him, then the entire sale will be annulled, and all the slaves will be returned. If this is not the case, then only that slave will be returned, and from the price, the buyer will take back from the seller the portion corresponding to the value of that slave.