Honoring Parents also applies to the "Have Not's"

Rabbi Shimon bar Yochai is of the opinion that G-d attaches greater importance to the honoring of parents than to honoring Himself: G-d is honored "with your substance," (Prov. 3:9) i.e., with that what He has graciously bestowed on man. If you have substance you are obligated to set apart tithes, to care for the poor and hungry, to purchase religious articles, etc.; and if you have not, you are not obligated to any of them. But when it comes to honoring parents, whether you have the means or not -- "Honor your father and your mother," even if you have to beg your living from door to door! [Yerushalmi, ibid.].