Musannaf Ibn Abi Shaybah

It is narrated from Hazrat Mughirah bin Shu'bah that the Holy Prophet (peace and blessings of Allah be upon him) forbade cursing the dead.

It is narrated from Hazrat Qutbah bin Malik that one of the leaders among the rulers insulted Hazrat Ali (may Allah be pleased with him, may Allah honor his face), so Hazrat Zaid bin Arqam (may Allah be pleased with him) stood up and said: Indeed, I know that the Noble Prophet (peace and blessings be upon him) forbade insulting the dead, so do not insult Hazrat Ali (may Allah be pleased with him); surely, he has passed away.

Hazrat Hilal bin Yasaf narrates that Hazrat Umar delivered a sermon on the mountain of Mina and said: Do not abuse the dead, because whoever abuses the dead causes distress to the living.

Hazrat Abdullah bin Umar (may Allah be pleased with them both) said: A person who abuses the dead is near to destruction and it is before him.

Hazrat Aisha (may Allah be pleased with her) said: "Mention your deceased only with goodness and virtue."

Hazrat Abdullah bin Masood (may Allah be pleased with him) said that causing distress to a believer after his death is just like causing him distress during his life.