Musannaf Ibn Abi Shaybah

Hazrat Mujahid (may Allah have mercy on him) narrates that once Hazrat Umar (may Allah be pleased with him) passed by the Messenger of Allah (peace and blessings be upon him) while Hazrat Aisha (may Allah be pleased with her) was also with him. Both of them were eating halwa. The Prophet (peace and blessings be upon him) called Hazrat Umar (may Allah be pleased with him) to join them. He (may Allah be pleased with him) put his hand along with their hands, and his hand touched the hand of Hazrat Aisha (may Allah be pleased with her). Upon this, he (may Allah be pleased with him) said: "Oh! If my opinion regarding her and her companions had been accepted, then neither she nor her companions would have been seen by any eye." This incident occurred before the command of hijab was revealed. Then, upon this, the verse was revealed.