But Jesus said it.
What do you think "Now, Father, glorify Me together with Yourself, with the glory which I had with You before the world was." means?
Do you not understand Jesus is speaking as part of His prayer to God the Father, asking to be glorified in His presence with the glory He had before the world began.
With the glory He had before the world began....
Perhaps you have verses that tell us something else?
I agree. But there is a verse that says “The Word became flesh…” (not ceased being God, but became flesh) John 1:14.
But he did empty himself . Jesus "emptied himself" to take on human form and serve humanity, demonstrating humility and obedience to God's will. This act is often understood as part of the Incarnation, where he became a servant and ultimately sacrificed himself for others.
But you will say not so, and I am not up to explaining.