“By faith Joseph, when his end was near, spoke about the exodus of the Israelites from Egypt and gave instructions about his bones” ( Hebrews 11:22 )
Speaking something about the future takes faith. Joseph is a great example of this. When the end of his life was drawing near he remembered the promise that God made to Abraham about the land he was to inherit and gave instructions for the Israelites to leave Egypt in pursuit of it.
“Then Joseph said to his brothers, “I am about to die. But God will surely come to your aid and take you up out of this land to the land he promised on oath to Abraham, Isaac and Jacob.” And Joseph made the sons of Israel swear an oath and said, “God will surely come to your aid, and then you must carry my bones up from this place” ( Genesis 50:24-25 ).
Whether or not Joseph understood the implications of these instructions doesn't really matter, Joseph gave them in faith so as to participate in the plan of God. Over four hundred years later this mass exodus took place just as Joseph prophesied or spoke forth.
Interestingly, Moses is the one who completed Joseph’s instructions, “Moses took the bones of Joseph with him because Joseph had made the sons of Israel swear an oath. He had said, “God will surely come to your aid, and then you must carry my bones up with you from this place” ( Exodus 13:19 ).
All of this originated by faith and one man of God having the courage to speak it so future generations would know what they were supposed to do. Joseph reminded the children of Israel of God’s promise and encouraged them to pursue it even when all seemed impossible because of their captivity. Today we call this history because it happened just as Joseph instructed.