John Gill Commentary Deuteronomy 28:14

"and shalt not turn aside from any of the words which I command you this day, to the right hand, or to the left, to go after other gods to serve them." — Deuteronomy 28:14 (ASV)

And you shall not go aside from any of the words which I
command you this day
Depart from them as a rule to walk by, turn out from them as a path to walk in, neglect and disobey them, and go into practices contrary to them: turning [to] the right hand or to the left, to go after other gods to serve
them ;
which to do was to break the first and principal table of the law, than which nothing was more abominable and provoking to God.