Sayyiduna Abdullah bin Buhaina (may Allah be pleased with him) narrated that the Messenger of Allah (peace and blessings be upon him) stood up after leading two rak'ahs of a prayer and did not sit for the first tashahhud, so the people also stood up with him. When he completed the prayer, we began to wait for him to say salam, but before saying salam, he said "Allahu Akbar" while sitting and performed two prostrations while sitting, then he said salam.