In the psalter there are a handful of longer psalms that not only offer prayer and praise (or, in this case, confession) to God, but also constitute a history lesson of sorts, taking in large expanses of the Old Testament with a panoramic view. As suggested in Year D, the preacher should not be put off by the comparative length of these psalms (78, 105, and 106), but instead recognize how condensed they are compared to the vast material they summarize, and leverage them accordingly as teaching tools.
Psalm 106 is one of these psalms, a short portion of which (106:1-6, 19-23) is used in RCL [Proper 23/Ordinary 28, Year A]. That lection consists of the opening Hallelujah, a call to thankful worship of the Lord (v. 1), an expression of wonder at God's mighty acts (v. 2), a promise of blessing for the righteous (v. 3), an individual petition for favor rooted in the sure conviction that the Lord will bless and deliver his people (vv. 4-5), a (truncated!) confession of sin, and a recollection of Israel's idolatry in the incident of the golden calf (vv. 19-23). The latter section ends on a hopeful note, however, as it recalls how the Lord relented from destroying them when Moses "stood in the breach" to intercede for them (v. 23).
The therapeutic power and the reforming potential of the psalm appears in the temporally or historically inclusive form in which the confession is introduced: "Both we and our ancestors have sinned; we have committed iniquity, have done wickedly" (v. 6). Unfortunately, by limiting the subsequent reading to the most familiar and famous case of idolatry, the effect of that repetitious confession is lost, along with the sense in which this psalm reminds the reader of "the perversity and obtuseness of the people" [New Oxford Annotated Bible with the Apocrypha, NRSV; OT p. 766]. Indeed, the threefold confession of v. 6 — in which one can almost hear a collective beating of the breast in grief and remorse — is matched with a similar pattern of repeated lapses on the part of the people, interspersed with reminders that the Lord continued to deliver them. That structure, which is even more apparent ad symmetrical in the following psalm (107), the lesson it has to convey, the light it has to cast forward on the ways in which "we" in our day have also sinner, and the redemptive power of this confessional psalm — all of this is lost when it is carved up into shorter pieces. Hence, this commentary itself should serve as a confession of one of Year D's errata. Ideally, the psalm should be left in tact, especially since it would appear we still have some matters that we have not confessed for some time.
What other sins, besides the golden calf, does this psalm confess?
(v.7a) — a failure to consider the Lord's wonders in Egypt;
(v. 7b) — failure to "remember the abundance of (his) steadfast love";
(vv. 7c-12) — rebellion at the Red Sea;
(v. 13) — forgetfulness and impatience;
(vv. 14-15) — testing God to serve the people's "wanton craving" (cf. Num 11:4-6, 31-35);
(vv. 16-18) — the pseudo-egalitarian rebellion of Korah, Dathan, and Abiram (Num 16);
(vv. 24-27) — general rebellion in refusing to enter the promised land (Num 14);
(vv. 28-31) — sexual rebellion involving the Baal of Peor;
(vv. 32-33) — complaint about a lack of water at Meribah of Kadesh;
(vv. 34-39) — failure to destroy the pagan nations and their idols, in lieu of which they came to imitate the pagans in practicing child sacrifice.
After this litany of Israel's apostasies, the psalm concludes with (1) a general confession of circumstances — oppression and subjection by their enemies — that met Israel when they provoked the Lord to anger (vv. 40-42); (2) a reminder of how the Lord continually responded to the cries of Israel with merciful deliverance, compassion, and steadfast love, ... and with regard for his covenant (vv. 43-46); and finally, (3) a petition for salvation from among the pagans, a promise, a blessing, and a call to worship (vv. 47-48).
Thus ends Book IV of the Psalms, with a penitential tour-de-force framed within doxological Hallelujahs; a bracing reminder, both in content and structure, that thoroughgoing confession is not a precursor to worship; it is worship; that is, confession is essentially of a piece with adoration itself, the humbling counterpart to the exaltation of the covenant-making Lord who is ever merciful, even in his anger, and ever faithful, even when we are not (2Tim 3:13).