This psalm also has no title to indicate the author, or to explain the occasion on which it was composed. It is a psalm of very special construction, and stands alone in the form of its poetry. The peculiarity consists in repeating at the close of each verse the language “for his mercy endureth forever.” This is a kind of refrains, and may have been designed, in public worship, to be a response by a choir, or by the people. That it may have been intended to be so used cannot be disproved, nor can anyone show that such a response in public worship is, itself, improper or wrong. It is not certain, however, that it was meant to be so used; and it should not, therefore, be appealed to as proving that such responses are proper in public worship, whatever may be true on that point. It may have been merely a specimen of the poetic art among the Hebrews - one of the forms in which Hebrew poetry expressed itself. The subjects referred to as laying the foundation for the response in each verse - “for his mercy endureth forever,” are such as have been often introduced in the previous psalms, and will require but little additional illustration. The general idea is, that all these acts of the divine interposition - all that God has done, even though it seemed to be a display of power or of justice, of severity or of wrath - was, in fact, an illustration of the “mercy” of God, and laid a foundation for praise. That is, All this was connected with the good of his people, with favors to mankind, with the accomplishment of great and benevolent purposes, and, therefore, was expressive of mercy - a proof that the “mercy of God endures forever.”