Is it permissible to hit and curse someone who insults the Companions after being warned?

The Companions are the disciples of the Messenger of Allah, peace and blessings be upon him, and followers of his religion. The Quran has spoken of their virtue, and a Muslim must recognize their status and beware of reviling and slandering them. This is a grave sin that does not harm the Companions but rather harms the reviler himself, as narrated by Aisha, may Allah be pleased with her.

What you did by severely beating the reviler is not considered enjoining good and forbidding evil with the hand; rather, it is a punishment. Punishments are primarily to be carried out by the Muslim ruler or his deputy. Furthermore, cursing a specific individual is not wise. It suffices you to curse generally whoever reviles the Companions of the Prophet, peace and blessings be upon him, as the Messenger of Allah, peace and blessings be upon him, said: "May Allah curse whoever reviles my Companions."