Allah directs Joseph to hide a goblet in his brother's saddlebag 12:70-79
12:70 And when he had given them their provisions, he hid a drinking-cup in his brother's saddlebag. Then a herald called out after them, 'Cameleers, you are thieves!'
12:76 He searched their bags before his brother's and then took out the goblet from his brother's bag. As such We directed Joseph. By the king's law he had no right to seize his brother unless Allah willed otherwise. We raise whom We will in rank; over every knowledgeable person is One who knows.
12:77 They said, 'If he is a thief know then that a brother of his has committed theft before him.' But Joseph kept it secret and did not reveal it to them. He said, 'You are in a worse position. And Allah knows well what you describe.'