These four verses are a fourfold picture of how heaven and earth ought to blend and harmonise.
I. Take the first verse: "Mercy and truth are met together," etc. We have here the heavenly twin sisters, and the earthly pair that corresponds. Mercy and Truth, two radiant angels, like virgins in some solemn choric dance, linked hand in hand, issue from the sanctuary and move amongst the dim haunts of men, making "a sunshine in a shady place;" and to them there come forth, linked in a sweet embrace, another pair, whose lives depend on the lives of their elder and heavenly sisters: Righteousness and Peace. (1) In man's experience righteousness and peace cannot be rent apart. (2) Righteousness and her twin sister Peace only come in the measure in which the mercy and the truth of God are received into thankful hearts.
II. In the eleventh verse "Truth shall spring out of the earth, and righteousness shall look down from heaven" we have God responding to man's truth. (1) Man's truth shall begin to grow and blossom in answer, as it were, to God's truth that came down upon it. (2) Righteousness shall look down from heaven, not in its judicial aspect merely, but as the perfect moral purity that belongs to the Divine nature, which shall bend down a loving eye upon the men beneath and mark the springings of any imperfect good and thankfulness in our hearts.
III. Then there is the third aspect of the ideal relation between earth and heaven set forth in the next verse: "Yea, the Lord shall give that which is good; and our land shall yield her increase;" that is to say, man responding to God's gift. The great truth is here developed that earthly fruitfulness is possible only by the reception of heavenly gifts.
IV. The last phase of the fourfold representation of the ideal relation between earth and heaven is, "Righteousness shall go before Him, and shall set us in the way of His steps;" that is to say, God teaching man to walk in His footsteps. Man may walk in God's ways, not only in the ways that please Him, but in the ways that are like Him. "Be ye therefore perfect, even as your Father which is in heaven is perfect."
A. Maclaren, A Year's Ministry,1st series, p. 15.