If you speak to your child through someone else, through – let’s say – a sitter; you mean what you say but your words have less of an impact than if you speak directly to your child. When God speaks to us through His Son, He speaks directly to us. He no longer uses a prophet to show us who He is. Instead, He shows us His very self by revealing Himself through the “heir of all things,” through the One “by whom He made the worlds” – that is, Jesus Christ.
“God, that spake sometime by prophets in many manners to our fathers, at the last in these days he hath spoken to us by the Son; whom he hath ordained heir of all things, and by whom he made the worlds.”