62 It is one and the same Lord Jesus Christ, the Word made flesh, Who expresses Himself in all these utterances, Who is man when He says He is abandoned to death: yet while man still rules in Paradise as God, and though reigning in Paradise, as Son of God commends His Spirit to His Father, as Son of Man gives up to death the Spirit He commended to the Father. Why do we then view as a disgrace that which is a mystery? We see Him complaining that He is left to die, because He is Man: we see Him, as He dies, declaring that He reigned in Paradise, because He is God.
Why should we harp, to support our irreverence, on what He said to make us understand His death, and keep back what He proclaimed to demonstrate His immortality? The words and the voice are equally His, when He complains of desertion, and when He declares His rule: by what method of heretical logic do we split up our belief and deny that He Who died was at the same time He Who rules? Did He not testify both equally of Himself, when He commended His Spirit, and when He gave it up? But if He is the same, Who commended His Spirit, and gave it up, if He dies when ruling and rules when dead: then the mystery of the Son of God and Son of Man means that He is One, Who dying reigns, and reigning dies.
Source: On the Trinity (New Advent)