John Gill Commentary Ezra 9:6

"and I said, O my God, I am ashamed and blush to lift up my face to thee, my God; for our iniquities are increased over our head, and our guiltiness is grown up unto the heavens." — Ezra 9:6 (ASV)

And said, O my God
Here begins the prayer of Ezra, and that with faith in God as covenant God, even when he was about to make confession of sin, and repentance for it; that prayer is right which is put up in faith, and that repentance genuine which is accompanied with faith, and flows from it:

I am ashamed, and blush to lift up my face to you, my God ;
a true sight and sense of sin causes shame and blushing, and never more than when a man is sensible of his covenant interest in God, and of his grace and favour to him, particularly in the forgiveness of his sin, see (Ezekiel 16:61Ezekiel 16:63)

for our iniquities are increased over our head ;
arisen and swelled like mighty waters, which seemed to threaten an overwhelming of them:

and our trespass is grown up unto the heavens ;
being done in an open, public, and insolent manner, and in such numbers, that they were, as it were, piled up in heaps, reaching to heaven, and calling down vengeance from there. Ezra includes himself as being one of the same nation; and these sins being so common were become national ones, which involved all the individuals, and exposed them to the divine resentment.