The first part of this Psalm (Psalms 108:1) is an enthusiastic utterance of adoration and thanksgiving, taken from Psalms 57:7-11. The second part (Psalms 108:6) is taken from Psalms 60:5-12. It is an appeal for help against Israel's enemies, grounded upon God's promise to apportion the land to His people, and give them dominion over the neighbouring nations.
Doubtless it was for liturgical use that these two fragments of older poems were combined into a new hymn. But at what time or under what circumstances this was done can only be conjectured. Apparently Israel was threatened by enemies, and the second part of Psalms 60 was felt to be an appropriate prayer for their needs. But the complaint of severe disaster with which that Psalm opens was not appropriate, and accordingly a thanksgiving was substituted for it. It seems natural to connect this thanksgiving with the repeated calls to thanksgiving in the preceding Psalms (Psalms 105:1 ff.; Psalms 106:1; Psalms 106:47; Psalms 107:1); and the prayer of the second part may have been prompted by some attack or threatened attack on the part of Edom or some other neighbouring nation upon the weak community of the Restoration. The old words of promise and prayer with their historical associations were adapted to new needs. Jehovah had restored His people to their home; thanksgiving for this proof of His lovingkindness and truth was their first duty: but they were exposed to the attacks of envious and malicious neighbours, and His aid was needed to maintain them in secure possession of the land.
Some such thought apart from the obvious application of Psalms 108:5 seems to have dictated the choice of this Psalm as a Proper Psalm for Ascension Day. On that day adoration and thanksgiving for Christ's triumph are fitly joined with prayer that He will put forth His power to give His Church the victory over her spiritual enemies.
This Psalm is of interest as proving that no scruple was felt in combining portions of other Psalms for liturgical purposes, and in prefixing to the new composition the title A Psalm of Davidwhich those Psalms bore. It justifies the assumption upon internal evidence that other Psalms (e.g. Psalms 19) are of composite origin.
Further it is to be noted that the revision of the second main division of the Psalter by the Elohistic editor (Introd. p. lv f.) must have preceded the compilation of this Psalm. Psalms 57, 60 were obviously in the compiler's hands in their -Elohistic" form, for in its use of Elohim, -God," instead of Jehovahthis Psalm forms a conspicuous exception to the regular usage of Book v.