Albert Barnes Commentary Numbers 15:2

"Speak unto the children of Israel, and say unto them, When ye are come into the land of your habitations, which I give unto you," — Numbers 15:2 (ASV)

To the Israelites of the younger generation is conveyed the hope that the nation should still enter into the land of promise. The ordinances that follow are more likely to have been addressed to adults than to children; and we may therefore assume that at the time of their delivery, the new generation was growing up, and the period of wandering drawing toward its close.

During that period, the meat-offerings and drink-offerings prescribed by the Law had probably been suspended because of the scanty supply of grain and wine in the wilderness. The command, therefore, to provide such offerings was a pledge to Israel that it should possess the land which was to furnish the resources for them.