Cambridge Bible for Schools and Colleges
Psalms 138 - Introduction
This Psalm may best be understood as an expression of the gratitude and confidence of Israel after the Return from the Captivity. Speaking in the name of the people the Psalmist praises Jehovah before all the world for the fulfilment of His promises (Psalms 138:1-3); anticipates the impression which the manifestation of His glory will make upon heathen nations (Psalms 138:4-6); and looks forward to the completion of His purposes for His people, in spite of further troubles that may await them (Psalms 138:7-8).
To the Hebrew title -A Psalm of David" some MSS of the Septuagint add of Haggai and Zechariah, or of Zachariah, possibly preserving a tradition that the Psalm belonged to the period of the Restoration, or suggesting that it fitly expressed the feelings of that period.
The tone and language of Psalms 138:4 resemble Psalms 102:15 ff., and many passages in Isaiah 40-66 where the hope of the conversion of the nations is connected with the Restoration of Israel from exile.