When Jacob learned that there was grain in Egypt, he said to his sons, "Why don't you do something?
I hear that there is grain in Egypt; go there and buy some to keep us from starving to death." 1
References for Genesis 42:2
So Joseph's ten half brothers went to buy grain in Egypt,
but Jacob did not send Joseph's full brother Benjamin with them, because he was afraid that something might happen to him.
The sons of Jacob came with others to buy grain, because there was famine in the land of Canaan.
Joseph, as governor of the land of Egypt, was selling grain to people from all over the world. So Joseph's brothers came and bowed down before him with their faces to the ground.