It's the Power of the King who speaks, not just our mouthing his words.
Jesus did nothing apart from the Father, he was dependent on the Holy Spirit & the Power of God. He spoke the Words of the Father. He was the expressed image of the Father, the Word walking on the earth.
The Word is empowered by the very person of God Himself.
The Word is a distinct expression of God's Power. The word of God upholds all things.