Sforno on Deuteronomy 17:2/ספורנו על דברים י״ז:ב׳

1כי ימצא בקרבך, after Moses instructed the people to appoint judges in each city so that each court would judge primarily people who lived in its vicinity, Moses continues with the trial of an idolater, something that is not judged locally, in the town where he lives, but in the town in which he committed the crime. Subsequently, Moses deals with the problem of disagreements among members of the court, or several courts with one another. Such disagreements are also not to be judged locally but “in the place that the Lord has chosen,” (verse 8) i.e. the same court in which an elder who refuses to submit to the majority view of his colleagues is to be judged.

2לעבור בריתו, the covenant embracing all the commandments, for worshipping idols is an offence considered as equivalent to having violated all of the Torah’s commandments.