Musnad Abu Ya'la al-Mawsili 42:18

Abu Khaythama narrated to us, Yahya narrated to us, from Shu'bah, Qatadah narrated to me, from 'Abdullah ibn Abi 'Utbah, from Abu Sa'id al-Khudri, who said: The Messenger of Allah (peace and blessings of Allah be upon him) was more bashful than a virgin in her private quarters. And he said: The Hour will not be established until the House is not performed Hajj to.