Charles Ellicott Commentary Deuteronomy 29:6

"Ye have not eaten bread, neither have ye drunk wine or strong drink; that ye may know that I am Jehovah your God." — Deuteronomy 29:6 (ASV)

You have not eaten bread —but manna (Deuteronomy 8:3).

Neither have you drunk wine or strong drink. —A fact stated here only, and evidently coming from the lips of one who “knew their walking through the wilderness.” They drank of that spiritual rock that followed them; and that Rock was Christ. God cared for their physical health and strength by the natural food which He gave them, and made their natural food represent the act of feeding upon Him. It is observable also that God seems to have especially blessed the abstinence from wine and strong drink for His sake in Israel. (See Lamentations 4:7.)

See Deuteronomy 3:1-17.