The Punishment of One Who Insults the Prophets and the Vicegerents

The Prophet (SAWA) said, 'Whoever insults any of the prophets, kill him; and he who insults a vicegerent is as one who has insulted a prophet.

Imam al-Sadiq (AS) when he was asked about someone who insulted the Prophet (SAWA), replied, 'The most inferior person [in society] must kill him, and if not him, then the second most inferior, and so on until at the last resort he must be killed by the imam [leader of the congregational prayer].