Negative commandment · Lo Ta’aseh #223 of 613
Not to reap fruit that grows on trees in the seventh year in the same manner as in an ordinary year
שלא לאסוף פירות האילן בשביעית כדרך שאוספין בכל שנה ושנה
The verse · Vayikra 25:5
אֵת סְפִיחַ קְצִירְךָ לֹא תִקְצוֹר וְאֶת־עִנְּבֵי נְזִירֶךָ לֹא תִבְצֹר שְׁנַת שַׁבָּתוֹן יִהְיֶה לָאָרֶץ
“That which grows of its own accord of thy harvest thou shalt not reap, nor gather the grapes of thy undressed vine: for it shall be a year of rest for the land.”
The Rambam’s words
Not to reap fruit that grows on trees in the seventh year in the same manner as in an ordinary year, as [Leviticus, ibid.] continues: "...and do not gather the grapes of your vines from which you must abstain."
שלא לאסוף פירות האילן בשביעית כדרך שאוספין בכל שנה ושנה, שנאמר "ואת עינבי נזיריך לא תבצור" (ויקרא כה,ה).
Why · Sefer HaChinuch #329
That we not gather the fruit of the trees in the seventh year in the manner that we gather them in every year
“It is from the roots of this commandment to affix in our hearts and make a strong impression in our minds [about] the matter of the world having been created.”
Who & when
“And there you will find in which place and at what time it is practiced.”
Where in the Mishneh Torah
Hilchot Sabbatical Year and the Jubilee הלכות שמיטה ויובל