{To him that knoweth} (eidoti). Dative case of second
perfect participle eid(9373) (from oida), and with the infinitive
to know how, "to one knowing how." {To do good} (kalon poiein).
"To do a good deed." {And doeth it not} (kai m(8820)poiounti).
Dative again of the present active participle of poie(935c), "and to
one not doing it." Cf. "not a doer" ( 1:23 ) and  Mt 7:26 . {Sin}
(hamartia). Unused knowledge of one's duty is sin, the sin of
omission. Cf.  Mt 23:23 .