Musnad Ahmad 30:618

'Abd al-Razzaq narrated to us, Ma'mar informed us, from al-Zuhri, from Ibn al-Musayyib, from Abu Hurayrah, who said: The Messenger of Allah, peace and blessings of Allah be upon him, said: "Journeys are not to be undertaken except to three mosques: the Sacred Mosque, this mosque of mine, and al-Aqsa Mosque."