Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) narrates: When the Prophet Muhammad (peace and blessings be upon him) had two people perform li'an (mutual cursing), when the man was about to say the fifth statement, the Prophet (peace and blessings be upon him) instructed a person to place his hand over his mouth. The narrator named Sufyan sometimes narrated these words in this narration: "Indeed, this (fifth statement) will make it obligatory (i.e., if he is lying, the punishment will become necessary)."