Manners In Islam: To Curse the Infidel

It is reported by Sayyidina Abu Hurayrah RA that the Messenger of Allah was asked to invoke curse on the polytheists.

The Prophet (PBUH) said, “I have not been sent to curse anyone but i have been sent as a mercy (for all).”
(Muslim)

Explanation:
The Holy Prophet (PBUH) refrained from invoking a curse on the polytheists even and from praying against them. He said, “I am mercy.” He asserted that he was sent as a mercy for his ummah and it is incumbent on them also that they follow the path of mercy.