A. Yusuf Ali:Translation:
And (Joseph) told his servants to put their stock in
trade 1722 (with which they had bartered) into their
saddle-bags, so they should know it only when they
returned to their people, in order that they might
come back. 1723

Muhammad Asad:Translation:
And [Joseph] said to his servants: "Place their merchandise 60 in their camel-packs, so that they may find it there when they come home, and hence be the more eager to return. 61
1722 Bida'ah: stock in trade; capital with which business is carried on; money when it is used as capital for trade. It is better here to suppose that they were bartering goods for grain. Cf. 12:19 .
1723 It was more important for Joseph's plan that they should come back. If they came back at all, they could not come without Benjamin after what he had told them. As an additional incentive to their coming back, he returns the price of the grain in such a way that they should find it in their saddlebags when they reach home.