כִּ֤י תַחְבֹּט֙ זֵֽיתְךָ֔ לֹ֥א תְפָאֵ֖ר אַחֲרֶ֑יךָ לַגֵּ֛ר לַיָּת֥וֹם וְלָאַלְמָנָ֖ה יִהְיֶֽה׃ (ס)
When thou beatest thine olive-tree, thou shalt not go over the boughs again; it shall be for the stranger, for the fatherless, and for the widow.
Read kabbalistic (mystical) interpretation of Deuteronomy 24:20: and classical mystical sources.