Charles Ellicott Commentary Deuteronomy 9:26

"And I prayed unto Jehovah, and said, O Lord Jehovah, destroy not thy people and thine inheritance, that thou hast redeemed through thy greatness, that thou hast brought forth out of Egypt with a mighty hand." — Deuteronomy 9:26 (ASV)

I prayed therefore ... and said. —The words that follow are very similar to those which are recorded in Exodus 32:11-13. Moses appears to be alluding to his first intercession here, before he descended from Sinai for the first time.