“It’s all right,” he said. “Don’t be afraid. Your God, the God of your father, has given you treasure in your sacks; I received your silver.” Genesis 43:23
God had indeed put their treasure back in their sacks after their first visit to Egypt to buy grain. He didn't do it by making it miraculously appear there, but by taking Joseph into slavery, then into Potiphar's house, then into prison, then into the palace, then into the position of power he now occupied. That is not less miraculous (it's possibly more), it just seems less spectacular at the time.
God works in mysterious ways. Sometimes dramatic and spectacular, sometimes in a series of events seemingly random at the time but 'miraculously' strung together in hindsight.
It's easy when looking back in my life to see how God used random events together for a specific purpose. It's not easy to see that in the middle of them because they appear so random. I am in the middle of a sequencye of those events that God is using to bring about his purposes right now. How do I know? Because I always am!