Sayyiduna Miswar bin Yazid al-Asadi (may Allah be pleased with him) says: I was present with the Messenger of Allah (peace and blessings be upon him) in the prayer, and while reciting he (peace and blessings be upon him) left out something in between. A man said: O Messenger of Allah! You left out such-and-such a verse. The Messenger of Allah (peace and blessings be upon him) said: "Then why did you not remind me of it?" He said: I thought it had been abrogated.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الجمعة / 5782