As it is written in the law of Moses - The word law was given to all the writings of Moses. See the notes at Luke 24:44.
Yet made we not our prayer before the Lord our God - Margin, “entreated we not the face of.” The Hebrew word used here (חלה châlâh) means, properly, “to be polished;” then to be worn down in strength, to be weak; then to be sick, or diseased; then in Piel (the form used here), to rub or stroke the face of anyone, to soothe or caress, and hence, to beseech, or supplicate. See Gesenius, “Lexicon” Here it means, that, as a people, they had failed, when they had sinned, to call upon God for pardon; to confess their sins; to implore his mercy; to deprecate his wrath. It would have been easy to turn aside his threatened judgments if they had been penitent, and had sought his mercy, but they had not done it. What is here said of them can and will be said of all sinners when the Divine judgment comes upon them.
That we might turn from, our iniquities - That we might seek grace to turn from our transgressions. “And understand thy truth.” The truth which God had revealed; equivalent to saying that they might be righteous.