Musannaf Ibn Abi Shaybah 4571 — What one does on forgetting

Muhammad (bin Sirin) said: Sayyiduna Imran bin Husayn (may Allah be pleased with him) led us in prayer in the mosque. He stood up after praying two rak'ahs, or sat down after praying three rak'ahs; Hisham's strongest opinion is that he sat after the two rak'ahs. When he had completed the prayer, he performed the two prostrations of forgetfulness.