De Moor V:11: The Procession of the Holy Spirit and John 15:26
Finally, Ἐκπόρευσις/Procession is attributed to the Holy Spirit, John 15:26. When to the Holy Spirit is attributed Going Forth, Procession, Ἐκπόρευσις, in the passage cited, this is done in a more restricted sense to indicate the Mode of Subsistence, whereby the Spirit is distinguished from the Father and the Son, while in a different sense Goings Forth are also attributed to the Son, Micah 5:2, concerning which passage I spoke in § 731, 732. And, that the passage cited in John on the term Ἐκπορεύεται, He proceeds, is to be understood of that sort of eternal and internal Procession of the Spirit, which is terminated internally; not of a Procession temporary and external, which is terminated upon the creatures, for the sanctifying of which He is sent forth, etc.: appears to be altogether evident from this, that, 1. Ἐκπόρευσις/Procession here is manifestly distinguished from the Sending. 2. In the words, ὃ παρὰ τοῦ Πατρὸς ἐκπορεύεται, which proceedeth from the Father, is described the Person of this Witness to be sent by the Son, so that He might give testimony concerning Him; to prove in this manner the ἀξιοπιστίαν/trustworthiness of His testimony: He proceedeth from the Father; therefore, He is consubstantial with Him, as is the Son also through His eternal Goings Forth, Micah 5:2, and hence is αὐτόπιστος/self-authenticating. 3. Concerning the temporal Sending of the Spirit are wont to be used the terms ἔρχεσθαι, to come, ἐπέρχεσθαι, to come upon, πέμπεσθαι, to be sent, in the Gospels, especially John, and in Acts, Matthew 3:16; John 14:26; 15:26; 16:7, 8, 13; Acts 19:6; Luke 1:35; Acts 1:8; but not ἐκπορεύεσθαι, to proceed, which here occurs; although this also is found to have been used of the granting of the super-abounding Grace of the Holy Spirit to the Church once in the New Testament, Revelation 22:1. 4. The present tense, in which this verb is set forth, while speech concerning His temporal Going Forth and Sending is wont to be made in the future and is thus made here; is an indiction that the eternal and internal Procession is being treated: see GERHARD’S Harmoniam Euangelicam, chapter CLXXVIII, tome 2, pages m. 292-294. For, the account of the present tense in the case of this verb, which the Most Illustrious LAMPE funishes in his Commentario with respect to the Economic Going Forth of the Spirit from the Father, that Christ was not yet perfected through sufferings, through which one-by-one He was obliged to acquire the Spirit; is of no great moment, and is refuted by this, that the Most Illustrious Man himself also adduces, that the Spirit, as the Spirit of Christ, testified in the Prophets concering His sufferings and glory: indeed, the Spirit of Christ is not denominated from Christ as only from the object of His testimony, but as altogether from Him also, who sent Him as an envoy to testify in the Prophets: and the Father, sending the Spirit before this, did that no less than afterwards in the name of His Son: compare LAMPE himself in his Dissertationum philologico-theologicarum, volume II, Disputation VII, chapter VIII, § 10, 11, pages 245, 246.
 John 15:26: “But when the Comforter is come (ἔλθῃ), whom I will send (πέμψω) unto you from the Father, even the Spirit of truth, which proceedeth from the Father (ὃ παρὰ τοῦ πατρὸς ἐκπορεύεται), he shall testify of me…”  Matthew 3:16: “And Jesus, when he was baptized, went up straightway out of the water: and, lo, the heavens were opened unto him, and he saw the Spirit of God descending (καταβαῖνον) like a dove, and lighting upon him…”  John 14:26: “But the Comforter, which is the Holy Ghost, whom the Father will send (πέμψει) in my name, he shall teach you all things, and bring all things to your remembrance, whatsoever I have said unto you.”  John 16:7, 8: “Nevertheless I tell you the truth; It is expedient for you that I go away: for if I go not away, the Comforter will not come (οὐκ ἐλεύσεται) unto you; but if I depart, I will send (πέμψω) him unto you. And when he is come (ἐλθὼν), he will reprove the world of sin, and of righteousness, and of judgment…”  John 16:13a: “Howbeit when he, the Spirit of truth, is come (ἔλθῃ), he will guide you into all truth…”  Acts 19:6: “And when Paul had laid his hands upon them, the Holy Ghost came on them (ἦλθε τὸ Πνεῦμα τὸ Ἅγιον ἐπ᾽ αὐτούς); and they spake with tongues, and prophesied.”  Luke 1:35: “And the angel answered and said unto her, The Holy Ghost shall come upon thee (ἐπελεύσεται ἐπὶ σέ), and the power of the Highest shall overshadow thee: therefore also that holy thing which shall be born of thee shall be called the Son of God.”  Acts 1:8: “But ye shall receive power, after that the Holy Ghost is come upon you (ἐπελθόντος τοῦ Ἁγίου Πνεύματος ἐφ᾽ ὑμᾶς): and ye shall be witnesses unto me both in Jerusalem, and in all Judaea, and in Samaria, and unto the uttermost part of the earth.”  Revelation 22:1: “And he shewed me a pure river of water of life, clear as crystal, proceeding (ἐκπορευόμενον) out of the throne of God and of the Lamb.”  See Hebrews 2:10; 5:8, 9.  See 1 Peter 1:11.