1268/1 - Ibn ‘Umar (may Allah be pleased with him and his father) reported: “The Messenger of Allah (may Allah’s peace and blessings be upon him) used to observe I‘tikāf during the last ten nights of Ramadan.” [Narrated by Al-Bukhāri and Muslim]
1269/2 - ‘Ā’ishah (may Allah be pleased with her) reported that the Prophet (may Allah’s peace and blessings be upon him) used to observe I‘tikāf during the last ten nights of Ramadan until he died. Then, his wives observed I‘tikāf after him. [Narrated by Al-Bukhāri and Muslim]
1270/3 - Abu Hurayrah (may Allah be pleased with him) reported: “The Prophet (may Allah’s peace and blessings be upon him) used to observe I‘tikāf during each Ramadan for ten days. In the year in which he died, he observed I‘tikāf for twenty days.” [Narrated by Al-Bukhāri]
1) It is Sunnah to observe I‘tikāf in Ramadan and be devoted to worship.
2) We are encouraged to seek out the night of Qadr during the last ten nights, at the time of I‘tikāf, given the special merit it has. A fortunate believer would seize virtuous times for performing acts of worship.
3) A main purpose behind I‘tikāf is to devote one’s heart and body for worship, away from worldly preoccupations that distract him from worshiping his Lord.
The phrases some people say and hang on walls in the mosque, such as “I intend to observe I‘tikāf in this mosque as long as I remain in it”, are not prescribed by the Shariah, neither by the Prophet’s actions nor his statements. He did not instruct us saying: When you enter a mosque, harbor the intention for I‘tikāf at any time. Rather, we may observe I‘tikāf for a day or a night, and more, and preferably along with fasting. This general intention, however, is not part of the prescribed guidance.