With slight modifications, Psalm 108 is made up of Psalm 57:7-11 (vv. 1-5) and Psalm 60:5-12 (vv. 6-13). Scholars are not sure what occasioned this new combination, but it may have risen out of the crisis of a new threat from foreign enemies. Through praise the psalmist expresses confidence in God (st. 1) and vows to praise the LORD among the nations for being faithful and merciful (st. 2). The psalmist proclaims God's glory above the heavens and over all the earth (st. 3), and then prays, "Save us and help us" (v. 6), O God, from the threat of our enemy (st. 4). Recalling God's commitments to parcel out the land of Canaan to the tribes of Israel (st. 5), the psalmist asks, Who will lead us in triumph if God has rejected us (st. 6)? Then comes this confession: Our only hope is God, and he will not fail us (st. 7). The versification is significantly altered from that in the 1912 Psalter.
Bert Polman, Psalter Hymnal Handbook
The Canons of Dort V, 13 explain that our assurance of eternal security and perseverance cannot “produce immorality or lack of concern for godliness in those put back on their feet after a fall, but it produces a much greater concern to observe carefully the way which the Lord prepared in advance” and it is “an incentive to a serious and continuous practice of thanksgiving and good works...” (Canons of Dort V, 12) Therefore, this sub-section contains songs which express both the desire and the commitment of the believer to walk in obedience for holy living. Woven throughout these songs are expressions of fervent desire for holy living, a dedication to follow God’s will, a surrender of one’s will, and prayers for the Holy Spirit to continue his sanctifying work.