Musannaf Ibn Abi Shaybah

Hasan narrates that a red velvet cloth was placed in the blessed grave of the Prophet (peace and blessings be upon him), which had come as booty from the Battle of Khaybar, because the soil of Madinah was salty and loose.

Hazrat Ibn Abbas (may Allah be pleased with both of them) narrates that a red velvet cloth was placed in the blessed grave of the Holy Prophet (peace and blessings be upon him and his family).