Interpretation and exegesis of Psalm 66 -- Hans-Joachim Kraus

From PSALMS 60 - 150 (1993 Fortress Press Edition: translation by Hilton C. Oswald):
SETTING:
Verses 1 to 7 contain a choral hymn.  The whole world is called on in the introit to sing to Yahweh and to see his great deeds (verses 3 following, then 5 and following).  Which deeds are meant?

Verse 6 provides the answer: Yahweh turned the sea into dry land, and Israel was able to "march through the stream / sea / river."  The walk through the river and the liberation of the people of God form the real main theme of the choir hymn (verses 1 - 7) and probably also of the grateful song of praise attached (verses 8 to 12). 
But where does the hymnic representation of the miracle of the sea and of Israel's passage through it have its actual locale?  In verse 6 we read: "There (s-h-e-m) we will rejoice!"  Which place is meant?

Verse 6 describes the crossing: "They march through the stream on foot" (most likely the Jordan : compare Psalm 114:3, 5 and Joshua 3:17).  Yet in the interest of realism the Jordan River is looked upon as the "great stream" and is crossed -- corresponding to the crossing of the sea (a festal situation that re-enacted the miracle of the sea and the crossing of the Jordan).  In this way, verses 1 - 12 could originally have been associated with a festival of passage. . .and of entrance into the land. . . Exulting and singing, the community "remembers" the mighty deeds of God and draws "all the world" into the song of praise.

The situation is entirely different in verses 13 - 20.  Here an individual who has been heard in his affliction presents vows of praise and offerings before Yahweh.  The worshipper comes into the sanctuary and there tells of the wonders God has performed (verses 13 & 16).  . . The two main assertions of Psalm 66 [ "Yahweh liberates his people" and "Yahweh helps an individual person" ] are coordinated with each other.  The salvific deed an individual has experienced is coordinated with the act of salvation in Israel, but it is at the same time also subordinated.  All the help and deliverance experienced by the individual have their origins and source in the salvation that has mightily made its appearance in Israel.  Here the Lord has come forward who performs frightening deeds (verse 3), brings the soul of his people to life (verse 9), and through fire and water lets it attain to liberty (verse 12).[excerpted and adapted from pages 35 - 38]