אֵ֣ת סְפִ֤יחַ קְצִֽירְךָ֙ לֹ֣א תִקְצ֔וֹר וְאֶת־עִנְּבֵ֥י נְזִירֶ֖ךָ לֹ֣א תִבְצֹ֑ר שְׁנַ֥ת שַׁבָּת֖וֹן יִהְיֶ֥ה לָאָֽרֶץ׃
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.
Read kabbalistic (mystical) interpretation of Leviticus 25:5: and classical mystical sources.