John Calvin Reformed @genevareformer

Daniel here continues his confession of sin. As we have already stated, he ought to begin here, because we must remark in general the impossibility of our pleasing God by our prayers, unless we approach him as criminals, and repose all our hopes on his mercy. But there was a special reason for the extraordinary nature of the Prophet’s prayers, and his use of fasting, sackcloth, and ashes.

Matthew Henry Presbyterian @wholebiblehenry

We have here Daniel's prayer to God as his God, and the confession which he joined with that prayer: I prayed, and made my confession. Note, In every prayer we must make confession, not only of the sins we have been guilty of (which we commonly call confession), but of our faith in God and dependence upon him, our sorrow for sin and our resolutions against it.

Commenting on Daniel 9:4-19

John Gill Reformed Baptist @doctorgill

We have sinned, and have committed iniquity, and have done wickedly, and have rebelled,.... Some think there is a gradation in these words; that they had committed some sins through error and ignorance; others through infirmity and obliquity, or in the perverseness of their spirits, and the crookedness of their ways; and others wilfully and in malice, in the wickedness of their hearts; and others...