John Gill Commentary Deuteronomy 18:19

"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." — Deuteronomy 18:19 (ASV)

And it shall come to pass, that whosoever will not hearken
unto my words
To the doctrines of the Gospel, but slight and despise them:

which he shall speak in my name ;
in whose name he came, and whose words or doctrines he declared them to be; not as his own, but his Father's, (John 5:43) (7:16) .

I will require it of him ;
or, as the Targums of Onkelos and Jonathan,

``my Word shall require it of him, or take vengeance on him;''

as Christ the Word of God did in the destruction of the Jewish nation, city, and temple; see (Luke 19:27Luke 19:44) .