Today's sermon discusses the 1) testimony of Jesus - that He spoke from His own authority, in contrast to prophets, and 2) the triune nature of Jesus' words - when Jesus speaks, He is not quoting the Father, but that the Father also speaks.
“He who comes from above is above all, he who is of the earth is from the earth and speaks of the earth. He who comes from heaven is above all. What He has seen and heard, of that He testifies; and no one receives His testimony. He who has received His testimony has set his seal to this, that God is true. For He whom God has sent speaks the words of God; for He gives the Spirit without measure. The Father loves the Son and has given all things into His hand. He who believes in the Son has eternal life; but he who does not obey the Son will not see life, but the wrath of God abides on him.”