My past research on Zechariah 4:6 turned up so many good resources and points that I would like to add a few thoughts to my earlier post about the verse:
Orthodox Jewish Bible: "Then he answered and spoke unto me, saying, This is the Devar Hashem unto Zerubavel, saying, Not by might, nor by ko’ach (power), but by My Ruach [Hakodesh], saith Hashem Tzva’os."
Rotherham Emphasized Bible: "Then responded he, and spake unto me, saying, This, is the word of Yahweh, unto Zerubbabel, saying,—Not by wealth, nor by strength, but by my spirit, saith Yahweh of hosts."
Robert Alter (The Hebrew Bible):
Two Foci With Which I'm Concerned:
1) What is the ruach YHWH in Zechariah 4:6?
2) In what sense is Jehovah (YHWH), "Yahweh of hosts"?
Concerning the first question, how most readers tend to understand the ruach YHWH has long been shaped by church theology. How many theologians have read the third person of the Trinity into passages that mention God's ruach? More than we care to recount now. Nevertheless, an objective reading of the Hebrew Bible reveals that God's ruach is not a person but more akin to a power: Jehovah's Witnesses believe the holy spirit (ruach) is Jehovah's active force that constantly emanates from him in order to accomplish his sovereign will.
The first mention of this ruach, which some understand to be "wind," is Genesis 1:2. Later in Judges 14:6, 19, the Hebrew Bible mentions the ruach YHWH becoming active on Samson.
Alan J. Hauser (The Genesis Debate) makes these points about the ruach YHWH in the Hebrew Bible:
"Let us briefly examine the use of 'spirit of God' in the Old Testament. The first part of the phrase, 'spirit of,' is commonly used in the construct state in Hebrew to denote the motivating force or dynamic power of a person or of God. In 2 Chronicles 36:22 we are told that 'the Lord stirred up the spirit of Cyrus king of Persia' to issue a proclamation allowing worshipers of Israel's God to rebuild His temple (cf. Ezra 1:1). In 1 Chronicles 5:26 God stirs up 'the spirit of Pul king of Assyria - that is, the spirit of Tiglath-Pileser king of Assyria' to carry away some of the tribes of Israel" (pages 118, 119).
Additionally from Hauser:
"In these instances 'spirit of' does not denote an entity in any way separate from the person but rather the active, forceful power of that person (cf. also Gen. 45:27; 2 Kings 2:15; 1 Sam. 30:12; Hag. 1:14). Why should we presume that it is different when the object of the phrase 'spirit of' is God? When we are told in Judges 14:6 that the 'spirit of the LORD came mightily upon' Samson, and that Samson tore apart the lion, does this mean that the Holy Spirit seized Samson? What is meant instead is that God's power came upon Samson and gave him strength (see also, for example, Judg. 6:34, 11:29). There is no hint of a separate person within the Godhead from the Father acting upon the individual."
I would phrase matters slightly different and contend that God exerts his power through the holy spirit, a non-personal force that belongs to the Father, but Hauser makes the point well: the ruach YHWH is not depicted as a person in the Hebrew Bible.
After his sin with Bathsheba, King David implored Jehovah in Psalm 51:10-12, cast me not from your presence, and do not take your holy spirit away from me. For the king and former shepherd, God's ruach is good and it leads David in the way of righteousness (Psalm 143:10). So he begs Jehovah to teach him because David knows the ruach of God is good, and it directs God's people in the appropriate way. See 1 Samuel 16:13; 2 Samuel 23:2.
Now in Zechariah 4:6, within the context of building the Second Jewish temple amidst opposition, the inspired prophet foretells that this building work will be done not by human might or military force: it will only be effected by God's ruach--the ruach YHWH. Ralph L. Smith explains (Vol. 32 of the WBC Series):
"There are really two words from Yahweh here (4:6–7 and 8–10a) but they both say essentially the same thing. One, the temple will be built. Zerubbabel started the rebuilding and he will finish it. Two, strength to finish the temple will not be man’s physical ability or military might , but will be by the power of the Spirit of Yahweh of hosts (4:6)."
What about the divine title, Yahweh of hosts?
"The interpreting angel attributed the divine quote to 'the LORD Almighty.'315 The Hebrew term ([ṣə·ḇā·’ō·wṯbôt]) is usually translated 'Almighty' or 'Hosts' and also connotes a military image, emphasizing the compelling power and authority that the Lord uses to accomplish whatever he wills.316 This unfathomable power belonging to the Lord awaits the people of God through his agent, the Spirit of the Lord."
Klein, George. New American Commentary Vol. 21B: Zechariah (Kindle Locations 4865-4869). B&H Publishing. Kindle Edition.
Whether one translates "the LORD Almighty," Yahweh of hosts or "Jehovah of armies," some questions arise as to whether entities on earth, stars or angels are meant by the word "hosts/armies." Could it be both stars and angels (i.e. spirit creatures)? The context doesn't necessarily make clear the intended meaning, so either meaning is possible. It doesn't appear that we can be dogmatic about the expression.