2. All the difficulties and oppositions that lie in the way shall be got over and removed, even those that seem insuperable (v. 7): Who art thou, O great mountain? Before Zerubbabel thou shalt become a plain. See here, (1.) How the difficulty is represented; it is a great mountain, impassable and immovable, a heap of rubbish, like a great mountain, which must be got away, or the work cannot go on. The enemies of the Jews are proud and hard as great mountains; but, when God has work to do, the mountains that stand in the way of it shall dwindle into mole-hills; for see here, (2.) How these difficulties are despised: "Who art thou, O great mountain! that thou shouldst stand in God's way and think to stop the progress of his work? Who art thou that lookest so big, that thus threatenest, and art thus feared? Before Zerubbabel, when he is God's agent, thou shalt become a plain. All the difficulties shall vanish, and all the objections be got over. Every mountain and hill shall be brought low when the way of the Lord is to be prepared," Isa. xl. 4. Faith will remove mountains and make them plains. Christ is our Zerubbabel; mountains of difficulty were in the way of his undertaking, but before him they were all levelled; nothing is too hard for his grace to do.