וְכׇל־הָעָ֖ם יִשְׁמְע֣וּ וְיִרָ֑אוּ וְלֹ֥א יְזִיד֖וּן עֽוֹד׃
all the people will hear and be afraid and will not act presumptuously again.
Torah Temimah points to Sanhedrin / Sifrei.
וכל העם ישמעו. מלמד שצריכין להכריז.
English: And all the people shall hear — this teaches that a public proclamation is required.
The execution of the rebellious elder must be publicized so that the community learns the lesson.
Derash on the verse (Sifrei) — not a formal named middah of the 13.
The death of the zaken mamre is accompanied by a public announcement so that the people hear and fear.