The Geneva Bible Translation Notes, [1599], at sacred-texts.com
(a) Which was ever in the midst of the temple, signifying that the graces of God's Spirit would shine, here in most abundance, and in all perfection.
(b) Which conveyed the oil that dropped from the trees into the lamps, so that the light never went out: and this vision was to strengthen and encourage the faithful that God had sufficient power in himself to continue his graces, and to bring his promise to pass even though he had no help from man.
Then he answered and spoke to me, saying, This [is] the word of the LORD to (c) Zerubbabel, saying, Not by (d) might, nor by power, but by my spirit, saith the LORD of hosts.
(c) Who was a figure of Christ, and therefore this doctrine was directed to all the Church who are his body and members.
(d) He shows that God's power alone is sufficient to preserve his Church, even though he does not use man's help to do it.
Who [art] thou, O (e) great mountain? before Zerubbabel [thou shalt become] a plain: and (f) he shall bring forth its headstone [with] shoutings, [crying], Grace, grace to it.
(e) He compares the power of the adversaries to a great mountain, who thought the Jews were nothing with regard to them, and would have hindered Zerubbabel, who represented Christ, whom the enemies daily labour to stop in the building of his spiritual Temple, but all in vain.
(f) Though the enemies think to stop this building, yet Zerubbabel will lay the highest stone of it, and bring it to perfection, so that all the godly will rejoice, and pray to God that he would continue his grace and favour toward the Temple.
The hands of Zerubbabel have laid the foundation of this house; his hands shall also finish it; and (g) thou shalt know that the LORD of hosts hath sent me to you.
(g) Meaning, the Prophet, that I am Christ sent from my Father for the building and preservation of my spiritual temple.
For who hath despised the day of (h) small things? for they shall rejoice, and shall see the (i) plummet in the hand of Zerubbabel [with] those seven; (k) they [are] the eyes of the LORD, which run to and fro through the whole earth.
(h) Signifying that all were discouraged at the small and poor beginnings of the temple.
(i) By which he signifies the plummet and line, that is, that Zerubbabel who represented Christ, would go forward with his building to the joy and comfort of the godly, though the world was against him, and though his own for a while were discouraged, because they do not see things pleasant to the eye.
(k) That is, God has seven eyes: meaning, a continual providence, so that neither Satan nor any power in the world, can go about to bring anything to pass to hinder his work; (Zac 5:9).
Then said he, These [are] the two (l) anointed ones, that stand by the Lord of the whole earth.
(l) Which were always green and full of oil, so that still they poured forth oil into the lamps: signifying, that God will continually maintain and preserve his Church, and endue it still with abundance and perfection of grace.