Later text
When the Advocate comes, whom I will send to you from the Father—the Spirit of truth who proceeds from the Father—He will testify about Me. And you also must testify, because you have been with Me from the beginning.
Intertextuality Pair
Allusion
Later text
When the Advocate comes, whom I will send to you from the Father—the Spirit of truth who proceeds from the Father—He will testify about Me. And you also must testify, because you have been with Me from the beginning.
Earlier text
“You are My witnesses,” declares the LORD, “and My servant whom I have chosen, so that you may consider and believe Me and understand that I am He. Before Me no god was formed, and after Me none will come. I, yes I, am the LORD, and there is no Savior but Me. I alone decreed and saved and proclaimed—I, and not some foreign god among you. So you are My witnesses,” declares the LORD, “that I am God.
In Isaiah 43:8-13 the LORD summons the nations to court and calls Israel to the stand: "You are My witnesses." Their testimony is that "there is no Savior but Me" (43:11), and they can give it because He has acted and foretold His acts. In John 15:26-27 Jesus promises "the Spirit of truth who proceeds from the Father—He will testify about Me. And you also must testify, because you have been with Me from the beginning." The tie is clear: the same witness vocabulary (martyreō, G3140; the Greek of Isaiah 43:10 has martys, G3144) and the same setting of a hostile world (15:18-25). The striking change is the subject of the testimony. Isaiah's witnesses testify that the LORD alone saves; the Spirit and the apostles testify about Jesus. Testimony once borne to the only Savior is now borne to the Son, because in Him that Savior has come. The disciples' witness is not a burden laid on them but the overflow of having been with Him.