At the same time, if you compare the Commentarium of the Most Illustrious LAMPE on John 15:26, with his apology against the Reverend Fruytier, Dissertationum philologico-theologicarum, volume II, Disputation VI, chapter VI, de Spiritu Sancto, pages 194-224, and Disputation VII, chapter VIII, § 27-41, pages 259-272), he is not to be arraigned on the charge of heresy, because he judged that the Ἐκπόρευσιν παρὰ τοῦ πατρὸς, procession from the Father, in John 15:26, certainly supposes a Natural relation to the Father and Order in the divine Essence; but in such a way that it most nearly regards a certain Economic Order, through which divine Wisdom willed to shed light upon this mystery and awesome βάθος/depth of the divine Essence; which Economic order he thinks masterfully to be intended here. So much the less, when he rightly argues that in the Order of the operation of the divine Persons in the Economy of Grace the Order of subsistence is manifestly supposed, which thence is also learned: whence from the Sending of the Spirit by the Son the argument is everywhere wont to be sought for the natural Going Forth of the Spirit, and the Mode of His Subsistence from the Son, equally as from the Father: he observes that already in the Creation He is called His Spirit because of this natural and eternal Relation; and he more than once testifies that he completely differs from Röellius in explaining the personal and characteristic Property of the Holy Spirit, Dissertationum philologico-theologicarum, chapter VI, § 12, pages 202, 203, and chapter VIII, § 34, page 266; and in the exegesis of the passage of John he appeals to the consent of Beza, Calvin, Walther, Cocceius, Amyraut, Johann Heinrich Heidegger, and others, chapter VI, § 7, page 199, to whom the Dutch translators in the marginal Notes are able to be added, writing on the word Uytgaat/procession, number 63, Namelijk, zo ten aenzien syns Persoons, welkers eigenschap is van den Vader en van den Zoon van eeuwigheid uyt te gaan, als ten aanzien van zyne kracht en werkinge, namely, as well in respect of His person, whose property it is to go forth from the Father, and from the Son from everlasting, as in respect of His power and working. While THYSIUS in Synopsi purioris Theologiæ, Disputation IX, § 12, has: “But let me illustrate that passage in which it is said, the Spirit of truth, who proceeds from the Father, John 15:26. Indeed, all the Ancients understand this of the eternal Procession of the Holy Spirit, but some of the More Recent Men understand it of that which is done in time, of ἐνερείας/activity and operation: we, on the other hand, comprehend both, the former indeed primarily, but the latter secondarily.” LAMPE further frees himself from suspicion of fault, when he says in his Dissertationum philologico-theologicarum, chapter VI, § 19, page 206, that by the Spiration and Procession of the Holy Spirit, as His Personal and Characteristic Notion, is intended “the Essential Order of the subsistence and operation of the Third Person relative to the Father and the Son, which Order is the deep foundation of all external operations, and concerning which, although Sacred Scripture has revealed certain general things as necessary to be known for preservation from error, more specific things have not been disclosed, etc.:” which things he thereafter undertakes to explain and confirm one by one and painstakingly; showing that by this Spiration and Procession a fixed and constant Order is indicated, which is applicable to the Holy Spirit relative to the Father and the Son: that in this way is indicated the Holy Spirit’s proper order, not only of operation, but also of subsistence, through which He subsists, no less than acts, not from Himself, but from the Father and the Son: that in this way the Essential Relation of the Spirit to the Father and the Son is signified, that is, 1. which necessarily pertains to the Essence of God; and which, 2. contains nothing that perfectly agree with God’s Most Perfect Essence, etc. Nevertheless, all the modes of speaking employed by the Most Illustrious LAMPE in his explication of this matter I would not make my own; neither do the reasons of the exegesis of the text of John 15:26 adduced by him appear to me to be of great weight: for example, 1. That the natural character of the expression implies external manifestation so clearly that, unless it was thus to be taken, it had necessarily required an explanation of the Holy Spirit; but this no more obtains here than in the מוֹצָאוֹת, goings forth, attributed to the Son, Micah 5:2. 2. The same thing might be said on the parallel passages that the Most Illustrious Man enumerates, in which a circular argument obtains, and a thing controverted is time and again illustrated by a thing equally controverted. 3. That the context of the present passage certainly favors the explanation of this Ἐκπορεύσεως/ Procession concerning the Holy Spirit’s personal and eternal Mode of subsistence, I have shown above. 4. That the verb Ἐκπορεύεσθαι, to proceed, is used of the Holy Spirit in Revelation 1:16; 4:5; 19:15, 21, was not to be supposed, but proven, and is denied by us. 5. If the natural Procession of the Spirit be treated here, it is necessary that that be derived from the Son also, and no reason is given why the Father alone is mentioned in this relation to the Spirit; this is recklessly repeated, since the Spirit is able to be said in one passage simply to proceed from the Father with respect to the Mode of His subsistence, and in other passages He is called the Spirit of the Father, and again the Spirit of the Son of God and the Spirit of Christ, inasmuch as the positing of the one does not exclude the other: and a reason is given why in this passage the Spirit is affirmed to proceed from the Father, and not at the same time from the Son; it has already been indicated in part above, and will be indicated in part at the end of this paragraph: compare LAMPE himself, chapter VII, de Spiritu Sancto, § 16, Disputation VI, page 235. 6. It is incorrectly concluded, that, if from the Sending of the Spirit by the Son it is rightly gathered, that the Spirit proceeds, or has His subsistence, from Son as well as from the Father, then such a Procession ought to be understood here, namely, an economic one, of which sort is Sending. For Sending, which involves a terminum ad quem and is set forth in the future, is necessarily economic: but, when Economy follows Nature, the manner of operation following the manner of subsistence, we rightly ascend from the former to the latter, and rightly assert that the Spirit to be sent by the Son also subsists from Him; likewise we also conclude the same thing concerning this from similar phrases used concerning the Spirit relative to the Father, John 14:16, 26. But it is something quite different concerning the language of Ἐκπορεύσεως/Procession that involves a terminum a quo, not likewise necessarily a terminum ad quem outside of the divine Essence, and is set forth in the present; while in the same context is perfectly joined with His economical Sending a consideration of the Spiriti’s Natural Mode of Subsistence, on which His economical Sending is founded; in a similar manner, in Micah 5:2, with the temporal, human Nativity of Messiah is joined His eternal, divine Nativity. THEODORET, Hæreticarum fabularum, book V, chapter III, opera, tome 4, pages 257, 258, writes admirably on these words of John, ὃ παρὰ τοῦ πατρὸς ἐκπορεύεται, which proceedeth from the Father: Τῷ δὲ εἰπεῖν, ἐκ τοῦ Πατρὸς ἐκπορεύεται, ἔδειξε πηγὴν ὄντα τοῦ Πνεύματος τὸν Πατέρα, καὶ οὐκ εἶπεν ἐκπορεύσεται, ἀλλ᾽ ἐκπορεύεται, δεικνὺς καὶ τῆς φύσεως τὴν ταυτότητα, καὶ τῆς οὐσίας τὸ ἄτμητον, καὶ ἀδιάφορον, καὶ τὸ ἡνωμένον τῶν ὑποστάσεων. τὸ γὰρ ἐκπορευόμενον, ἀχώριστον ἐξ οὗ ἐκπορεύεται, In saying, He proceedeth from the Father, He exhibited the Father as the fount of the Spirit; and He did not say, He will proceed, but He proceedeth, revealing the identity of nature, and the indivisible and common being, and the unity of the persons : for the one proceeding is undivided from the one sending forth.
 Rudolph Walther (1519-1586) was a German Reformed theologian; he was a student of Bullinger, and then his associate and fellow-laborer; and latter successor in the leadership of the church in Zurich. Walther’s sermons on the New Testament survive.  While studying at Saumur, Moïse Amyraut (1596-1664) was heavily influenced by hypothetical universalism of Scottish theologian John Cameron. He served as professor at Saumur (1633-1664), together with Louis Cappel and Josué de la Place.  Johann Heinrich Heidegger (1633-1698) was a Swiss Reformed theologian, serving as Professor of Theology at Steinfurt (1659-1665), and then at Zurich (1667-1698).  Revelation 1:16: “And he had in his right hand seven stars: and out of his mouth went a sharp two-edged sword (καὶ ἐκ τοῦ στόματος αὐτοῦ ῥομφαία δίστομος ὀξεῖα ἐκπορευομένη): and his countenance was as the sun shineth in his strength.”  Revelation 4:5: “And out of the throne proceeded (ἐκ τοῦ θρόνου ἐκπορεύονται) lightnings and thunderings and voices: and there were seven lamps of fire burning before the throne, which are the seven Spirits of God.”  Revelation 19:15: “And out of his mouth goeth (ἐκ τοῦ στόματος αὐτοῦ ἐκπορεύεται) a sharp sword, that with it he should smite the nations: and he shall rule them with a rod of iron: and he treadeth the winepress of the fierceness and wrath of Almighty God.”  Revelation 19:21: “And the remnant were slain with the sword of him that sat upon the horse, which sword proceeded out of his mouth (τῇ ἐκπορευομένῃ ἐκ τοῦ στόματος αὐτοῦ): and all the fowls were filled with their flesh.”  See Matthew 10:20.  See Galatians 4:6.  See Romans 8:9; 1 Peter 1:11.  That is, a boundary to which.  That is, a boundary from which.  That is, a boundary to which.