John 17:5

5. With thine own self In blessed and eternal society with thy own nature.

Glory which I had… before the world That is, the glory which I, as eternal Logos, had with the eternal God. See note on John 1:1. Into that glory admit me, the incarnate Logos, so that the God-man shall be eternally recognized as eternally divine. The eternal Logos and the incarnate Logos are the same person in different eras of existence. So that the incarnate Logos could claim on earth that as Logos he possessed an eternal glory in heaven, to which he might ascend and therewith be invested.

Before the world was The term world here includes the entire universe of worlds. Some have affirmed that God has eternally been creating worlds after worlds. In that case the priority of the glory of the Logos would be rather priority in the order of nature than of time, as regards the absolute universe.