With this assurance the Lord had fully granted the request of the people, "according to all that thou desiredst of the Lord thy God;" and Israel, therefore, was all the more bound to hearken to the prophets, whom God would raise up from the midst of itself, and not to resort to heathen soothsayers. (On the fact itself, comp. Deuteronomy 5:20. with Exodus 20:15-17.) "In the day of the assembly," as in Deuteronomy 9:10; Deuteronomy 10:4. - The instructions as to their behaviour towards the prophets are given by Moses (Deuteronomy 18:19, Deuteronomy 18:20) in the name of the Lord, for the purpose of enforcing obedience with all the greater emphasis. Whoever did not hearken to the words of the prophet who spoke in the name of the Lord, of him the Lord would require it, i.e., visit the disobedience with punishment (cf. Psalm 10:4, Psalm 10:13). On the other hand, the prophet who spoke in the name of the Lord what the Lord had not commanded him, i.e., proclaimed the thoughts of his own heart as divine revelations (cf. Numbers 16:28), should die, like the prophet who spoke in the name of other gods. With וּמת, the predicate is introduced in the form of an apodosis.

Deuteronomy 19:3 Parallel Commentaries

Isaiah 35:8 And an highway shall be there, and a way, and it shall be called The way of holiness; the unclean shall not pass over it...

Isaiah 57:14 And shall say, Cast you up, cast you up, prepare the way, take up the stumbling block out of the way of my people.

Isaiah 62:10 Go through, go through the gates; prepare you the way of the people; cast up, cast up the highway; gather out the stones...

Hebrews 12:13 And make straight paths for your feet, lest that which is lame be turned out of the way; but let it rather be healed.