Neginoth in the superscription of Psalm 67 likely means, as the NKJV translates it here and in other places, "stringed instruments."

George Knight's Daily Study Bible Series commentary Psalms says: "Obviously this psalm was composed for public worship. Perhaps it belonged particularly to the autumn harvest festival [i.e., the Feast of Tabernacles or Ingathering] (see verse 6)" (comments on verses 1-7). This he takes from the RSV, which renders verse 6 as "The earth has yielded its increase," whereas other translations understand the verb here as future tense—“shall yield." Of course, the annual harvest does portray a future harvest, as was pointed out with respect to Psalm 65, which begins the current grouping of psalms—and that is certainly a major theme here as well.

The song opens with a prayer for God's mercy and blessing and that His face would shine—smile in favor—on His people (Psalm 67:1). As previously pointed out in regard to Psalm 31:16, the language here is taken from the priestly blessing of Numbers 6:25 (see also Psalm 4:6; Psalm 44:3; Psalm 80:3, Psalm 80:7, Psalm 80:19; Psalm 119:135). The Zondervan NIV Study Bible says that this song's "content, form and brevity suggest that it served as a liturgical [i.e., worship service] prayer of the people at the conclusion of worship, perhaps just prior to (or immediately after) the priestly benediction" (note on Psalm 67).

"God's blessing on his people (as well as his saving acts in their behalf) will catch the attention of the nations and move them to praise (Psalm 65:2)" (same note). Indeed, this is a rather exciting thought within the psalm. Note the repetition in the refrain of Psalm 67:3 and verse 5. The excitement here is not just for the increased praise for God, but for the fact that all peoples will be able to rejoice when they experience the establishment of His righteous government over all nations. In their happiness over this certain hope, God's people are expressing love for all mankind.

Given all this, the focus of verse 6 is clearly future. The earth yielding its increase speaks not only of God's great agricultural provision in the world to come, but of the great harvest of humanity that will then take place—to the "ends of the earth" (verse 7), as the nations learn to properly fear and respect Him and His people are vastly blessed as never before.