The Triune God in Isaiah 48

Hearken unto me, O Jacob and Israel, my called; I am He; I am the first, I also am the last. Mine hand also hath laid the foundation of the earth, and my right hand hath spanned the heavens: when I call unto them, they stand up together.

                      (Isaiah 48:12-13 KJV)

The individual speaking in these two verses can be identified as God. He claims to be the first and the last, something no one but God can claim. There is no one else besides Him. He is the uncreated first cause of all creation. In this passage He is shown to be the one who created the heavens and the earth. It is undisputable, this is God speaking.

As this passage continues God speaks of bringing future Judgement on Babylon who He will use as a chastisement upon His people, particularly the southern kingdom of Judah. When the time has come, God will raise up a Persian ruler named Cyrus to set His people free (see Isaiah 44:28-44:4).

It is still God speaking as we come to verse 16,

Come ye near to me, hear this; I have not spoken in secret from the beginning; from the time that it was, there am I: and now the Lord God and his Spirit, hath sent me.

                                ( Isaiah 48:16 KJV)

So notice that it is God speaking, who will be sent by the Lord God, and the Spirit. Here we have a clear view of the triune makeup of God. Again, it is obvious from the context that it is God speaking. No one but God can claim to be the first and last, the creator of the heavens and earth. That claim belongs only to God. Yet we see the Lord God, and the Spirit, sending the speaker who we have identified as God.

We can deduce from this portion of scripture that it prophetically speaks of the coming Messiah, Jesus, who will be annointed by the Holy Spirit. 

This is foretold also in Isaiah 42:1-7, and Isaiah 61:1-3, and confirmed by Jesus Himself when He read this passage in the synogogue, and claimed to be the fulfillment of it (Luke 4:16-21). Lest there be any doubt in our minds, Creation is ascribed to Jesus as well as it states in Hebrews 1:2-3, Col 1:16, and John 1:3, which reads, All things were made by him; and without him was not anything made that was made.

Notice the "There am I" statement denoting eternity. This is very close to Jesus' statement in John 8:58, "Before Abraham was, I am."

Here we have again seen Jesus portrayed as God, as well as another Old Testament passage which reveals the triune God.