Sayyidah Maymunah (may Allah be pleased with her), the freed slave-woman of the Messenger of Allah (peace and blessings be upon him), said: I said: O Messenger of Allah, give us a ruling about Bayt al-Maqdis. He (peace and blessings be upon him) said: "Go to it and pray in it." At that time those lands were in a state of war. "If you cannot go to it and pray in it, then send oil to be burned in its lamps."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 4316