I will sing of the mercies of the LORD for ever: with my mouth will I make known thy faithfulness to all generations.
Sing — He prefaces this, lest the following complainers of present miseries should argue ingratitude for former mercies.
Faithfulness — Whatsoever hath befallen us, it proceeded not from thy unfaithfulness.
 For I have said, Mercy shall be built up for ever: thy faithfulness shalt thou establish in the very heavens.
Establish — As firmly and durably as the heavens themselves.
 I have made a covenant with my chosen, I have sworn unto David my servant,
Chosen — With David; whom I have chosen to the kingdom.
 Thy seed will I establish for ever, and build up thy throne to all generations. /*Selah*/.
Build up — I will perpetuate the kingdom to thy posterity; which was promised upon condition, and was literally accomplished in Christ.
 And the heavens shall praise thy wonders, O LORD: thy faithfulness also in the congregation of the saints.
Heavens — The inhabitants of heaven.
Faithfulness — Understand, shall be praised; which supplements are usual in scripture.
 For who in the heaven can be compared unto the LORD? who among the sons of the mighty can be likened unto the LORD?
Among — The highest angels.
 God is greatly to be feared in the assembly of the saints, and to be had in reverence of all them that are about him.
Feared — With a fear of reverence.
Saints — The whole society of angels.
All that — That encompass his throne.
 O LORD God of hosts, who is a strong LORD like unto thee? or to thy faithfulness round about thee?
Round thee — Like a girdle encompassing thee. It appears in all thy words and works.
 Thou hast broken Rahab in pieces, as one that is slain; thou hast scattered thine enemies with thy strong arm.
Rhahab — Egypt.
 The north and the south thou hast created them: Tabor and Hermon shall rejoice in thy name.
Tabor — The several parts of the land of Canaan, both within Jordan, where mount Tabor is; and without it, where Hermon lies.
Rejoice — Shall be fruitful and prosperous, and so give their inhabitants cause to rejoice.
In — By thy favour.
 Justice and judgment are the habitation of thy throne: mercy and truth shall go before thy face.
Justice and judgment — Justice in judging.
 Blessed is the people that know the joyful sound: they shall walk, O LORD, in the light of thy countenance.
Know — Who enjoy the presence of God and his ordinances, to which they are called by the sound of trumpets.
Walk — Under the comfortable influences of thy favour.
 In thy name shall they rejoice all the day: and in thy righteousness shall they be exalted.
Name — In the knowledge and remembrance of thy name, of thy infinite power and goodness.
 For thou art the glory of their strength: and in thy favour our horn shall be exalted.
The glory — To thee alone belongs the glory of all their valiant achievements.
 Then thou spakest in vision to thy holy one, and saidst, I have laid help upon one that is mighty; I have exalted one chosen out of the people.
Vision — Which then was the usual way by which God spake to the prophets.
Holy one — To thy holy prophets; the singular number being put for the plural; especially to Samuel and Nathan.
Laid help — I have provided help for my people.
Upon — Upon a person of singular courage and wisdom.
 The enemy shall not exact upon him; nor the son of wickedness afflict him.
Exact — Not conquer him or make him tributary.
 I will set his hand also in the sea, and his right hand in the rivers.
Set — Establish his power and dominion.
The sea — The mid-land sea.
The rivers — Euphrates, called rivers, in regard of divers branches of it, and rivers which flow into it. So here is a description of the uttermost bounds of the promised land.
 Also I will make him my firstborn, higher than the kings of the earth.
My first-born — As he calls me father, verse 26, so I will make him my son, yea my first-born; who had divers privileges above other sons. This and the following passage in some sort agree to David, but are properly accomplished in Christ.
Higher — This also was in some sort accomplished in David, but more fully in the Messiah.
 His seed also will I make to endure for ever, and his throne as the days of heaven.
For ever — To sit upon the throne for ever, as the next words explain it. This was accomplished only in Christ.
 It shall be established for ever as the moon, and as a faithful witness in heaven. /*Selah*/.
A witness — The rainbow, which is God's faithful witness, a token of God's everlasting covenant between God and every living creature for perpetual generations, Genesis 9:12,16.
 But thou hast cast off and abhorred, thou hast been wroth with thine anointed.
But — Having hitherto declared the certainty of God's promises, he now humbly expostulates with God about it.
 The days of his youth hast thou shortened: thou hast covered him with shame. /*Selah*/.
Youth — The youthful and flourishing estate of David's kingdom was very short, and reached not beyond his next successor.
 Remember how short my time is: wherefore hast thou made all men in vain?
Short — Our time, the time of our king and kingdom, in whose name the psalmist puts up this petition.
Wherefore — Wherefore hast thou made us and our king (and consequently all other men, whose condition is nothing better than ours) in vain, or to so little purpose? Didst thou raise us and him, settle the crown upon David's head by a solemn covenant, and vouchsafe so many and great promises and privileges, and all this but for a few years, that our crown and glory should be taken from us, within a little time after it was put upon our heads?
 What man is he that liveth, and shall not see death? shall he deliver his soul from the hand of the grave? /*Selah*/.
What man — All men at their best estate are mortal and miserable; kings and people must unavoidably die by the conditions of their natures; and therefore, Lord, do not increase our affliction.
 Remember, Lord, the reproach of thy servants; how I do bear in my bosom the reproach of all the mighty people;
How I — We thy servants; our king and his people; of whom he speaks as of one person.
 Wherewith thine enemies have reproached, O LORD; wherewith they have reproached the footsteps of thine anointed.
Anointed — By whom he seems to understand either first the kings of Judah, the singular number being put for the plural; and by their footsteps may be meant either their ways or actions, or the memorials of their ancient splendor; or secondly the Messiah, whom the Jews continually expected for a long time, which being well known to many of the Heathens, they reproached the Jews, with the vanity of this expectation. And by the footsteps of the Messiah, he may understand his coming.
 Blessed be the LORD for evermore. Amen, and Amen.
Blessed — Let thine enemies reproach thee and thy promises concerning the sending of the Messiah, I will heartily bless and praise thee for them, and encourage myself with them.