Sayyiduna Abdullah bin Buhaynah (may Allah be pleased with him) said: The Messenger of Allah (peace and blessings be upon him) led one of the two evening prayers and did not sit after two rak'ahs. When he (peace and blessings be upon him) reached the end of the prayer, we waited for him (peace and blessings be upon him) to give the salam; the Messenger of Allah (peace and blessings be upon him) performed two prostrations before giving the salam, then he gave the salam.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 3814