It is a return to former glory for which He prays. Are we to regard this petition as exclusively the author's addition, on the lines of his theology of the pre-existent Logos, or the real expression of Christ's consciousness of former life with God, expressed in language which could be used in speaking to the Father, though He could not have used it in teaching men; or as a real expression of consciousness of pre-existence, in the sense which it would naturally have to the Jews of our Lord's own time (cf. Jeremiah 1:5), which the author interprets in the terms of his doctrine of pre-existence? In John 17:6-8 He pleads the accomplishment of His appointed work for those whom the Father has given Him, into whose hearts God has put it to accept the message. To them He has made known the nature of God. God gave them to Him to shepherd, and they have received and made effective in their lives His word. So they have learned the Divine origin of His teaching and the truth that God sent Him.
Related Commentaries of John 17:5
John 17:5-8
5 And now, O Father, glorify thou me with thine own self with the glory which I had with thee before the world was.
6 I have manifested thy name unto the men which thou gavest me out of the world: thine they were, and thou gavest them me; and they have kept thy word.
7 Now they have known that all things whatsoever thou hast given me are of thee.
8 For I have given unto them the words which thou gavest me; and they have received them, and have known surely that I came out from thee, and they have believed that thou didst send me.