lo'-fool (usually mishpaT, "relating to judgment," or "a pronounced judgment" tsaddiq, "relating to that which is righteous" or "just"; exesti, eunomos, "that which is authorized according to law," or "a privilege according to legitimate custom" (compare Eze 18:5,19, Eze 21:1-32,27; Isa 49:24; Mt 12:10; Ac 16:21; 19:39)): Used of persons: of God, as being righteous both in the punishment of the wicked and the rewarding of the righteous (Ps 145:17 Hebrew); of man, as being just and equitable in all his dealings with his fellow-man (Eze 33:19). It is used of things when the same are in accord with a pronounced judgment or a declared will of God, and thus pleasing in His sight (Mr 3:4). When the course of individual conduct is according to God's law of righteousness, it is declared to be "lawful" (Eze 33:19). The word is used in a forensic sense as declaring the legal status of a person conforming to law. The idea of straighthess, rigid adherence to God's law, whether religious, civil or ceremonial, cannot be excluded from the definition of the word "lawful."
Neither the King James Version nor the American Standard Revised Version is consistent in its translation of the Hebrew and Greek words translated "lawful." Ofttimes the words "just" and "righteous" are used. To arrive at the full and proper meaning of "lawful," therefore, it is necessary that we study the passages containing these synonymous terms. The written Law of God is the recognized standard by which things, actions and persons are to be judged as being lawful or unlawful.