Catena Aurea on John 17:1–5: Augustine of Hippo

But it is justly asked, how the Son can glorify the Father, when the eternal glory of the Father never experienced abasement in the form of man, and in respect of its own Divine perfection, does not admit of being added to. But among men this glory was less when God was only known in Judæa; and therefore the Son glorified the Father, when the Gospel of Christ spread the knowledge of the Father among the Gentiles. Glorify Thy Son, that Thy Son also may glorify Thee; i. e. Raise Me from the dead, that by Me Thou mayest be known to the whole world. Then He unfolds further the manner in which the Son glorifies the Father; As Thou hast given Him power over all flesh, that He should give eternal life to as many as Thou hast given Him. All flesh signifies all mankind, the part being put for the whole. And this power which is given to Christ by the Father over all flesh, must be understood with reference to His human nature.