i.e. I wholly abstained from all meat and drink. Compare 1 Kings 13:8,9,17 2 Kings 6:22.
Related Commentaries of Deuteronomy 9:9
Deuteronomy 9:9
9 When I was gone up into the mount to receive the tables of stone, even the tables of the covenant which the LORD made with you, then I abode in the mount forty days and forty nights, I neither did eat bread nor drink water: