Albert Barnes Commentary Psalms 106:6

"We have sinned with our fathers, We have committed iniquity, we have done wickedly." — Psalms 106:6 (ASV)

We have sinned with our fathers—We have sinned as “they” did; we have followed their example. The illustration of the manner in which the nation had sinned occupies a considerable part of the remainder of the psalm. The idea here is that, in the generation in which the psalmist lived, there had been the manifestation of the same rebellious spirit which had so remarkably characterized the entire nation. The “connection” of this with the foregoing verses is not very apparent.

It would seem that the psalmist was deeply impressed with a sense of the great blessings which follow from the friendship of God and from keeping his commandments—as stated (Psalms 106:3–5). But he remembered that those blessings had not come upon the people as might have been expected, and his mind suddenly turns to the cause of this: the fact that the nation had “sinned.” It was not that God was unwilling to bestow that happiness; it was not that true religion “failed” to confer happiness; but it was that the nation had provoked God to displeasure, and that, in fact, the sins of the people had averted the blessings which would otherwise have come upon them. The psalmist, therefore, in emphatic language—repeating the confession in three forms, we have sinned - we have committed iniquity, we have done wickedly—acknowledges that the failure was in them, not in God. The language here is substantially the same as in (Daniel 9:5–6), and it would seem not improbable that the one was suggested by the other.

Which was prior in the order of time, it is now impossible to determine. Compare the notes at Daniel 9:5-6.