It is narrated from Sayyiduna Ibn Umar (may Allah be pleased with them both) that once Sayyiduna Umar (may Allah be pleased with him) mentioned in the presence of the Messenger of Allah, "O Messenger of Allah! In the days of ignorance, I had vowed to perform i'tikaf for one night in Masjid al-Haram. What should I do now?" He said: "Fulfill your vow."