A: First,
it was compiled by Imam
Ahmad in his Musnad and
Abu Dawud in his Sunan narrated
on the authority of
`Aishah (may Allah be pleased with her) that the Prophet (peace be upon him) said:
Breaking a dead man's bone is like breaking it when he is alive.
This signifies
the sanctity of the dead and not interfering with him/her by harming or debasing their graves.
Second,
it is impermissible to curse a dead Muslim, as the Prophet (peace be upon him) said:
Do not abuse the dead, because they have attained that which they had forwarded (their deeds, good or bad).
You should perform Tawbah (repentance to Allah) and ask Allah's forgiveness for what you have done.May Allah grant us success. May Peace and blessings of Allah be upon our Prophet Muhammad, his family and Companions!