Albert Barnes Commentary Numbers 28:7

"And the drink-offering thereof shall be the fourth part of a hin for the one lamb: in the holy place shalt thou pour out a drink-offering of strong drink unto Jehovah." — Numbers 28:7 (ASV)

The original of the word “strong wine” שׁכר shêkār is a term usually employed to describe strong drink other than wine (Leviticus 10:9 note). The Israelites in the wilderness had, in their lack of wine, substituted shechar made from barley for it. They had thus observed the spirit, though not the letter of the ordinance. The drink-offering was either poured around the foot of the altar; or on the altar, and so upon the flesh of the sacrifice by which the altar was covered .