Jamieson, Fausset and Brown on Deuteronomy 9:12-29

12-29. Arise, get thee down quickly from hence; for thy people ... have corrupted themselves--With a view to humble them effectually, Moses proceeds to particularize some of the most atrocious instances of their infidelity. He begins with the impiety of the golden calf--an impiety which, while their miraculous emancipation from Egypt, the most stupendous displays of the Divine Majesty that were exhibited on the adjoining mount, and the recent ratification of the covenant by which they engaged to act as the people of God, were fresh in memory, indicated a degree of inconstancy or debasement almost incredible.