Punishing him was intended as a warning to others.
Tips
usage
儆 is a literary/formal character rarely seen alone. It most commonly appears in the idiom 以儆效尤 (yǐ jǐng xiào yóu) — 'to punish one as a warning to others', and in 儆戒 (jǐngjiè), meaning 'to warn / to admonish'.