See Deuteronomy 24:19-21. “Grape” signifies fallen fruit of any kind; and “vineyard” a fruit garden of any kind. Compare Deuteronomy 23:24.
The poor - is the poor Israelite - “the stranger” is properly the foreigner, who could possess no land of his own in the land of Israel.
9 And when ye reap the harvest of your land, thou shalt not wholly reap the corners of thy field, neither shalt thou gather the gleanings of thy harvest.
10 And thou shalt not glean thy vineyard, neither shalt thou gather every grape of thy vineyard; thou shalt leave them for the poor and stranger: I am the LORD your God.