《韩非子·内储说下六微》
您若不杀他，他就要拿济阳君受到魏国惩处的事去齐国报功了。
君杀之，是将以济阳君抵罪于齐矣。
If you do not kill him, he will take the matter of Lord Jiyang being punished by the State of Wei and use it to seek recognition in the State of Qi.