Musnad Ahmad 25:368

Yunus and ‘Affan narrated to us, they said: Hammad—meaning Ibn Salamah—narrated to us, from ‘Ali ibn Zayd. ‘Affan said: ‘Ali ibn Zayd informed us, from Yusuf ibn Mihran, from Ibn ‘Abbas, that a man came to ‘Umar and said: A woman came to pledge allegiance to me, so I took her into a private room and I obtained from her what is less than sexual intercourse. He said: Woe to you! Perhaps she is a woman whose husband is absent in the way of Allah? He said: Yes. He said: Go to Abu Bakr and ask him. He said: So he went to him and asked him, and he said: Perhaps she is a woman whose husband is absent in the way of Allah? He said: He said the same as what ‘Umar said. Then he came to the Prophet, peace and blessings of Allah be upon him, and he said the same to him. He said: "Perhaps she is a woman whose husband is absent in the way of Allah?" And the Quran was revealed: {And establish prayer at the two ends of the day and at the approach of the night. Indeed, good deeds do away with misdeeds} [Hud: 114] to the end of the verse. He said: O Messenger of Allah, is this for me specifically, or for the people generally? ‘Umar struck his chest with his hand and said: Neither for him nor for the delight of an eye, rather it is for the people generally. The Messenger of Allah, peace and blessings of Allah be upon him, said: "‘Umar has spoken the truth."