When thou reapest thy harvest in thy field, and hast forgot a sheaf in the field, thou shalt not go back to fetch it; it shall be for the stranger, for the fatherless, and for the widow . . . 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. When thou gatherest the grapes of thy vineyard, thou shalt not glean it after thee ; it shall be for the stranger, for the fatherless, and for the widow. . . .

(The Torah)