I will require it. Compare John 12:48, and Hebrews 4:12, where "discerner" means "able to judge" (Greek. kritikos). That "Word" is the "critic" (or judge), and will judge all other "critics".
Related Commentaries of Deuteronomy 18:19
Deuteronomy 18:19
19 And it shall come to pass, that whosoever will not hearken unto my words which he shall speak in my name, I will require it of him.