Chapter 33: Retiring to a Mosque for Remembrance of Allah (I'tikaf)

Narrated Abu Huraira: The Prophet (ﷺ) used to perform I 'tikaf every year in the month of Ramadan for ten days, and when it was the year of his death, he stayed in I 'tikaf for twenty days.
Sahih al-Bukhari 2044
Chapters
1 Revelation 2 Belief 3 Knowledge 4 Ablutions (Wudu') 5 Bathing (Ghusl) 6 Menstrual Periods 7 Rubbing hands and feet with dust (Tayammum) 8 Prayers (Salat) 9 Times of the Prayers 10 Call to Prayers (Adhaan) 11 Friday Prayer 12 Fear Prayer 13 The Two Festivals (Eids) 14 Witr Prayer 15 Invoking Allah for Rain (Istisqaa) 16 Eclipses 17 Prostration During Recital of Qur'an 18 Shortening the Prayers (At-Taqseer) 19 Prayer at Night (Tahajjud) 20 Virtues of Prayer at Masjid Makkah and Madinah 21 Actions while Praying 22 Forgetfulness in Prayer 23 Funerals (Al-Janaa'iz) 24 Obligatory Charity Tax (Zakat) 25 Hajj (Pilgrimage) 26 `Umrah (Minor pilgrimage) 27 Pilgrims Prevented from Completing the Pilgrimage 28 Penalty of Hunting while on Pilgrimage 29 Virtues of Madinah 30 Fasting 31 Praying at Night in Ramadaan (Taraweeh) 32 Virtues of the Night of Qadr 33 Retiring to a Mosque for Remembrance of Allah (I'tikaf) 34 Sales and Trade 35 Sales in which a Price is paid for Goods to be Delivered Later (As-Salam) 36 Shuf'a 37 Hiring 38 Transferance of a Debt from One Person to Another (Al-Hawaala) 39 Kafalah 40 Representation, Authorization, Business by Proxy 41 Agriculture 42 Distribution of Water 43 Loans, Payment of Loans, Freezing of Property, Bankruptcy 44 Khusoomaat 45 Lost Things Picked up by Someone (Luqatah) 46 Oppressions 47 Partnership 48 Mortgaging 49 Manumission of Slaves 50 Makaatib 51 Gifts 52 Witnesses 53 Peacemaking 54 Conditions 55 Wills and Testaments (Wasaayaa) 56 Fighting for the Cause of Allah (Jihaad) 57 One-fifth of Booty to the Cause of Allah (Khumus) 58 Jizyah and Mawaada'ah 59 Beginning of Creation 60 Prophets 61 Virtues and Merits of the Prophet (pbuh) and his Companions 62 Companions of the Prophet 63 Merits of the Helpers in Madinah (Ansaar) 64 Military Expeditions led by the Prophet (pbuh) (Al-Maghaazi) 65 Prophetic Commentary on the Qur'an (Tafseer of the Prophet (pbuh)) 66 Virtues of the Qur'an 67 Wedlock, Marriage (Nikaah) 68 Divorce 69 Supporting the Family 70 Food, Meals 71 Sacrifice on Occasion of Birth (`Aqiqa) 72 Hunting, Slaughtering 73 Al-Adha Festival Sacrifice (Adaahi) 74 Drinks 75 Patients 76 Medicine 77 Dress 78 Good Manners and Form (Al-Adab) 79 Asking Permission 80 Invocations 81 To make the Heart Tender (Ar-Riqaq) 82 Divine Will (Al-Qadar) 83 Oaths and Vows 84 Expiation for Unfulfilled Oaths 85 Laws of Inheritance (Al-Faraa'id) 86 Limits and Punishments set by Allah (Hudood) 87 Blood Money (Ad-Diyat) 88 Apostates 89 (Statements made under) Coercion 90 Tricks 91 Interpretation of Dreams 92 Afflictions and the End of the World 93 Judgments (Ahkaam) 94 Wishes 95 Accepting Information Given by a Truthful Person 96 Holding Fast to the Qur'an and Sunnah 97 Oneness, Uniqueness of Allah (Tawheed)