It is narrated from Sayyiduna Ibn Umar (may Allah be pleased with them both) that indeed Umar (may Allah be pleased with him) said: O Messenger of Allah (peace and blessings be upon him)! Indeed, I had made a vow in the days of ignorance that I would observe i'tikaf for one night in Masjid al-Haram. So the Messenger of Allah (peace and blessings be upon him) said: "Fulfill your vow."