Rashi on Leviticus 25:4/רש"י על ויקרא כ״ה:ד׳

1יהיה לארץ [A SABBATH OF STRICT REST] SHALL BE UNTO THE LAND [or SOIL] — unto the fields and vineyards.

2לא תזמר — The word is a denominative verb from זמורה, a branch, and denotes: to do something to the branches: it is used here because one lops off its (the vineyard’s) branches. Its translation in the Targum is thus: לא תכסח, “thou shall not cut off”, and this root has a similar meaning in the Hebrew (Isaiah 33:12) “as thorns cut off (כסוחים)”; (Psalms 80:17) “it is burnt with fire, it is cut down (כסוחה).