Some mention the following narration on Aishah reported by Abu Dawud in his sunnan to show some of its restrictions:
That ‘Aa’ishah (radhi-yallaahu `anhaa) said: ((the sunnah for he who is in i’tikaaf is that he does not visit the sick nor witness a funeral, nor touch a woman (his wife), nor have intercourse with her nor leave to fulfil a need except that which is necessary)).
Although this specific narration has been disputed pertaining to some of its wordings, and Allah knows best.
Ash-Shaykh Muqbil, said:
“If a person intends to do itikaaf in the month of Ramadan and he intends to leave to fulfill a task that he must perform such as going to exams at schools, then he can leave off doing itikaaf for that day and he can go to the school”
Also it is not a must he does it for all the ten days. However, it is greater in reward if he completes the ten days. When I was in Yemen, some of the shuyookh used to only get time to perform iktikaaf in the odd nights, and so they will perform itikaaf in those nights only.
It is recommended for the one in itikaaf to seclude himself from the distractions of the worldly affairs and be more devoted in acts of worship in the masjid such as in reading the Quran and in praying and doing dhikr and etc.
~ Abu Fajr AbdulFattaah bin Uthman
“When does the Mu’takif enter into Itikaaf?
There is a difference of opinion between the Scholars: is it on the night of the twentith or the night of the twenty first? The Majority of the Scholars say it is on the night of the twenty first.
Shaikh Ibn ul-‘Uthaymeen rahimahullah said: “The majority of the people of Knowledge say that he begins the Itikaaf from the night of the twenty first, not from the fajr of the twenty first. (This is the case) even though some scholars took the opinion that the beginning of Itikaaf is from the fajr of the twenty first and using as evidence the Hadith of Aisha in Bukhari: When he prayed Subh he entered his place of Itikaaf. However, the majority explained that the Messenger sallahu alayhi wa salam separated from the people that time. As for his intention of Itikaaf, it was from the night before the last ten nights which begins from the sunset of the day of the twenty”
[Fatawaa fi Ahkaam Siyaam Ibn Uthaymeen]
This is also the opinion of the four Imams, Imam al-Mubaarkfoori in Tuhfatul Ahwadhi, Shaikh Abdul Aziz ala Shaikh and others.
However, the more correct view is to start after fajr on the day of the twenty first.
Shaikh Bin Baz rahimahullah said:
“And it is recommended for the one making Itikaaf to enter his place of Itikaaf after Salahtul Fajr from the day of the twenty first following the Prophet sallahu alayhi wa salam” [Majmoo’ al-Fataawa Bin Baz(15/442)]
This is also the view of Imam al-Awzaai, Ibn Qayyim, Ibn Mundhir, and Imam as-San’aani in Subul as-Salam.
كَانَ رَسُولُ اَللَّهِ - صلى الله عليه وسلم -إِذَا أَرَادَ أَنْ يَعْتَكِفَ صَلَّى اَلْفَجْرَ, ثُمَّ دَخَلَ مُعْتَكَفَهُ
Whenever the Messenger of Allah (ﷺ) intended to make I’tikaf he would pray the morning prayer and then he would enter the place of his I’tikaf
When does he leave?
He also leaves after fajr on the last day.
Abu Said al-Khudri radiallahu anahu said:
اعتكفنا مع رسولِ اللهِ صلى الله عليه وسلم العشْرَ الأواسطَ ، فلما كان صبيحةُ عشرين، نقلنا متاعنا
We practiced I`tikaf with Allah’s Messenger (ﷺ) in the middle ten days (of Ramadan). In the morning of the twentieth (of Ramadan) we shifted our baggage…”
[Reported by al-Bukhari no. 2016]”
Faisal Ibn Abdul Qaadir Ibn Hassan