Verse 5. - For the Lord is good (comp. 1 Chronicles 16:34; 2 Chronicles 5:13; 2 Chronicles 7:3; Ezra 3:11; Psalm 106:1; Psalm 107:1; Psalm 118:1, 29; Psalm 125:3; Psalm 136:1; Psalm 145:9, etc.). His mercy is everlasting; literally, his mercy is forever. Compare the frequent refrain, "His mercy endureth forever" (Psalm 118:1-4, 29; Psalm 136:1-26, etc.). And his truth (or, his faithfulness) endureth to all generations; literally, to generation and generation. All men's hope is in God's "faithfulness," that he will keep his promises to them - pardon them, deliver them, cleanse them, and give them rest in his kingdom forever.

100:1-5 An exhortation to praise God, and rejoice in him. - This song of praise should be considered as a prophecy, and even used as a prayer, for the coming of that time when all people shall know that the Lord he is God, and shall become his worshippers, and the sheep of his pasture. Great encouragement is given us, in worshipping God, to do it cheerfully. If, when we strayed like wandering sheep, he has brought us again to his fold, we have indeed abundant cause to bless his name. The matter of praise, and the motives to it, are very important. Know ye what God is in himself, and what he is to you. Know it; consider and apply it, then you will be more close and constant, more inward and serious, in his worship. The covenant of grace set down in the Scriptures of the Old and New Testament, with so many rich promises, to strengthen the faith of every weak believer, makes the matter of God's praise and of his people's joys so sure, that how sad soever our spirits may be when we look to ourselves, yet we shall have reason to praise the Lord when we look to his goodness and mercy, and to what he has said in his word for our comfort.For the Lord is good,.... Both in a providential way, and in a way of grace, and does good; he is the good Shepherd, that has laid down his life for the sheep; and the good Samaritan, that pours in the wine and oil of his love and grace, and his precious blood, to the healing of the wounds made by sin: while he was on earth, he went about doing good to the bodies and souls of men; and he continues to do good unto them, and therefore should be praised, served, and worshipped:

his mercy is everlasting; or "his grace" (e); there is always a sufficiency of it for his people; and his lovingkindness, which may be also here meant, is always the same; having loved his own which were in the world, he loves them to the end, John 13:1.

and his truth endureth to all generations; or his faithfulness in fulfilling his promises, and performing his engagements; he was faithful to his Father that appointed him, and to the covenant he made with him; and he is faithful to his people, to keep what they commit to his care and charge now, and to give them the crown of righteousness at the last day, which is laid up for them; and upon all these considerations, and for these reasons, ought to be praised and adored.

(e) "gratia ejus", Cocceius, Gejerus; "gratia et misericordia ejus", Michaelis.