May not those waggons be figures of ordinances, which are designed to convey souls to our spiritual Joseph? When souls are bringing to CHRIST, the stuff of the earth will be considered as nothing. Philippians 3:7-8.
Related Commentaries of Genesis 45:19
Genesis 45:19-20
19 Now thou art commanded, this do ye; take you wagons out of the land of Egypt for your little ones, and for your wives, and bring your father, and come.
20 Also regarde not your stuff; for the good of all the land of Egypt is yours.