6:1 And I turned, and lifted up my eyes, and looked, and, behold, there came four {a} chariots out from between {b} two mountains; and the mountains [were] mountains of brass.
(a) By chariots here, as by horses before, he means the swift messengers of God to execute and declare his will.
(b) By the mountains he means the external counsel and providence of God, by which he has from before all eternity declared what will come to pass, and that which neither Satan nor all the world can alter.
6:1 Four chariots - Angels who are sometimes styled chariots of God. These as employed in the affairs of church and empire, act their part in the revolution and changes of things, 'till the gospel be preached by the Messiah, and the apostles. Of brass - These denote the immoveable decrees of God, his steady execution of his counsels and the insuperable restraints upon all empires and countries, which God keeps within the barriers of such impregnable mountains.
6:1-8 This vision may represent the ways of Providence in the government of this lower world. Whatever the providences of God about us are, as to public or private affairs, we should see them all as coming from between the mountains of brass, the immoveable counsels and decrees of God; and therefore reckon it as much our folly to quarrel with them, as it is our duty to submit to them. His providences move swiftly and strongly as chariots, but all are directed and governed by his infinite wisdom and sovereign will. The red horses signify war and bloodshed. The black, signify the dismal consequences of war, famines, pestilences, and desolations. The white, signify the return of comfort, peace, and prosperity. The mixed colour, signify events of different complexions, a day of prosperity and a day of adversity. The angels go forth as messengers of God's counsels, and ministers of his justice and mercy. And the secret motions and impulses upon the spirits of men, by which the designs of Providence are carried on, are these four spirits of the heavens, which go forth from God, and fulfil what the God of the spirits of all flesh appoints. All the events which take place in the world spring from the unchangeable counsels of the Lord, which are formed in unerring wisdom, perfect justice, truth, and goodness; and from history it is found that events happened about the period when this vision was sent to the prophet, which seem referred to therein.