Hadith 667
Lady Aisha (may Allah be pleased with her) narrates: I was eating sweet dish with the Prophet (peace and blessings be upon him) from the same bowl when Sayyiduna Umar (may Allah be pleased with him) passed by. The Prophet (peace and blessings be upon him) called him, and he also ate. His finger touched my finger, so he said: Oh, oh, alas! If the Prophet (peace and blessings be upon him) had accepted my opinion about you, no eye would have seen you. Then the verses of hijab were revealed.