4:6 The angel announced a word of explanation from Yahweh that Zechariah was to pass on to Zerubbabel, the descendant of David who was the leader of the first group of returnees from exile.88He was to tell him, "not by might [Heb. hayil] nor by power [Heb. koah] but by the Spirit [Heb. ruah] of Yahweh of hosts."
"This principle is an elliptical sentence: Not by might, nor by power, but by My Spirit, says the Lord of hosts,' a kind of motto, as it were, to guide all endeavors and enterprises of the nation in these evil days. If we were to complete the ellipsis we might formulate the statement somewhat after the following fashion: If success is to be gained in the achievements of the people of God it will not be secured by what man can do but by the Spirit's work."89
Since Zerubbabel was leading the rebuilding of the temple and the restoration of the community, the Lord's word to him was a word of encouragement. These restorations would not need an army of workers, as Solomon's temple did (1 Kings 5:13-18), nor unusually strong laborers. The strength of the workers, in fact, failed because the work was so strenuous (cf. Neh. 4:10). The work would succeed because of the supernatural grace (help) that the Lord would provided by His Spirit (cf. Gen. 1:2; Exod. 15:8, 10; 28:3; 31:3; Num. 11:17-29; Judg. 3:10; 6:34; 11:29; 13:25; 14:6, 19; 15:14, 19; 2 Sam. 22:16; Ezek. 37:1-14). This is, of course, true of any work that seeks to carry out God's will in the world (cf. 2 Cor. 12:9).
4:7 A great mountain would become a plain before Zerubbabel. Mountains are symbols of large obstacles (cf. Isa. 40:4; 41:15; 49:11; Matt. 17:20; 21:21; Mark 11:23; 1 Cor. 13:2).90The whole process of temple restoration seemed like a mountainous job to the few exiles who returned from exile. In addition, there was much opposition to building (Ezra 4:1-5, 24), and the Israelites themselves proved unwilling to persevere in the task (Hag. 1:14; 2:1-9). Nevertheless, God would reduce this mountain to a flat plain by assisting the workers.
Furthermore Zerubbabel would bring forth the top stone, the final stone on the project, with shouts of "Grace, grace to it."The joyful cry of the people as they saw the last stone put in place would voice their prayer that God's blessing would now rest on the beautiful structure that His grace had made possible.
"There is nothing that makes the heart of God's people more ready to overflow with the truest joy than to witness success or the fulfillment of God's promises in the work of the kingdom."91
