It is narrated from Yusuf, he says: Sayyiduna Muawiyah bin Abi Sufyan (may Allah be pleased with him) led them in prayer, that is, he acted as their imam. At one point, instead of sitting, he stood up. When the people said "Subhan Allah," he still stood up and continued the prayer. Then he performed two prostrations of forgetfulness (sujood as-sahw) while he was sitting after completing the prayer. Then he sat on the pulpit and said: I heard the Messenger of Allah (peace and blessings be upon him) say: Whoever forgets something in the prayer should perform two prostrations in this manner.