Albert Barnes Commentary Leviticus 25:5

"That which groweth of itself of thy harvest thou shalt not reap, and the grapes of thy undressed vine thou shalt not gather: it shall be a year of solemn rest for the land." — Leviticus 25:5 (ASV)

Vine undressed - That is, “unpruned”; literally “Nazarite vine,” the figure being taken from the unshorn locks of the Nazarite. (Numbers 6:5).