42 Does He not reveal to His Apostles the Dispensation of this glory by the express signification of the words, Now is the Son of Man glorified, and God is glorified in Him. If God has been glorified in Him, God has glorified Him in Himself, and straightway has He glorified Him. In the words, Now is the Son of Man honoured, and God is honoured in Him, we have first the glory of the Son of Man, then the glory of God in the Son of Man. So there is first signified the glory of the body, which it borrows from its association with the divine nature: and then follows the promotion to a fuller glory derived from an addition to the glory of the body. If God has been honoured in Him, God has honoured Him in Himself, and straightway has God honoured Him.
God has glorified Him in Himself, because He has already been glorified in Him. God was glorified in Him: this refers to the glory of the body, for by this glory is expressed in a human body the glory of God, in the glory of the Son of Man is seen the divine glory. God was glorified in Him, and therefore has God glorified Him in Himself: that is, by His promotion to the Godhead, whose glory was increased in Him, God has glorified Him in Himself. Already before this He was reigning in the glory which springs from the divine glory: from henceforth, however, He is Himself to pass into the divine glory. God has glorified Him in Himself: that is, in that nature by which God is what He is. That God may be all in all: that His whole being, leaving behind the Dispensation by which He is man, may be eternally transformed into divinity.
Nor is the time of this hidden from us: And God has glorified Him in Himself, and straightway has He glorified Him. At the moment when Judas arose to betray Him, He signified as present the glory which He would obtain after His Passion through the Resurrection, but assigned to the future the glory with which God would glorify Him with Himself. The glory of God is seen in Him in the power of the Resurrection, but He Himself, out of the Dispensation of subjection, will be taken eternally into the glory of God, that is, into God, the all in all.
Source: On the Trinity (New Advent)