Oecumenius — on Rev 1:4 (Commentary on Revelation)

“This is equivalent to saying, "Grace to you from God, the Father of all of you." For the Father names Himself, revealing Himself to the wisest Moses at the burning bush, saying, "I AM THE ONE WHO IS [ἐγώ εἰμι ὁ ὤν]." (Ex. 3:14) And indeed, concerning the Son, the divine evangelist present says, "In the beginning was the Word; and the Word was with God, and the Word was God." (Jn. 1:1) And again, in the first of the Catholic Epistles: "That which was from the beginning, which we have heard, which we have seen with our eyes, which we have looked upon, and our hands have handled, concerning the Word of life." (1 Jn. 1:1) "who is to come." This is the Holy Spirit. For the Spirit did not only come on the day of Pentecost, as recorded in the Acts (chapter 2), but He continually comes to receive souls worthy of Him.”