Romans 3:19

In order to bring home this testimony of Scripture more directly to the Jews, and to prevent any subterfuge by which they might attempt to shift the reference from themselves on to the Gentiles, the Apostle calls attention to the fact that the Law — i.e., the Old Testament, from which he has been quoting — speaks especially to those to whom it was given.

Saith... saith. — Different words are here used in the Greek; the first is applicable as much to the matter as to the utterance of that which is spoken, the second refers specially to the outward act by which it is enunciated or promulgated; this is addressed to certain persons.

Guilty before God. — Rather, guilty to God; the dative expresses the person to whom the penalty is due.