Genesis 42:3-8

So Joseph’s ten older brothers went down to Egypt to buy grain. But Jacob wouldn’t let Joseph’s younger brother, Benjamin, go with them, for fear some harm might come to him. So Jacob’s sons arrived in Egypt along with others to buy food, for the famine was in Canaan as well. Since Joseph was governor of all Egypt and in charge of selling grain to all the people, it was to him that his brothers came. When they arrived, they bowed before him with their faces to the ground. Joseph recognized his brothers instantly, but he pretended to be a stranger and spoke harshly to them. “Where are you from?” he demanded. “From the land of Canaan,” they replied. “We have come to buy food.” Although Joseph recognized his brothers, they didn’t recognize him.