Fiqh-us-Sunnah - 3.154

Hadith 3.154.1

Actions that Nullify the I'tikaf

If a person performs one of the following acts, his i 'tikaf will be nullified: Intentionally leaving the mosque without any need to do so, even if it is for just a short time. In such a case, one would not be staying in the mosque, which is one of the principles of i'tikaf.
Abandoning belief in Islam, as this would nullify all acts of worship. If you ascribe a partner to Allah, your work will fail and you will be among the losers.
Losing one's reason due to insanity or drunkenness, or the onset of menstruation or post-childbirth bleeding, all of which disqualifies a person for i'tikaf.
Sexual intercourse. Allah says: "But touch them not [that is, your wives] and be at your devotions in the mosque."
However, one may touch his wife without there being any desires. One of the Prophet's wives would comb his hair while he was performing i'tikaf. As for kissing or touching due to desire, Abu Hanifah and Ahmad say that it is not desirable, for it leads to something that is forbidden for the one performing i'tikaf. However, it does not nullify it unless one ejaculates. Malik says that it nullifies the i'tikaf, for it is an illegal touch regardless of whether the person involved ejaculates or not. From ash-Shaf~i there are two reports that correspond to the two preceding opinions.
Ibn Rushd explains that: "The reason for their differences of opinion is [the (fact) that] if a word has more than one meaning, one being literal and the other figurative, does the word apply at one time to all of them or not? This is one of the types of words that have more than one meaning. Those who say that it carries both meanings interpret 'touch' in the 'ayah . . . 'and touch them not and be at your devotions in the mosque' in the unrestrictive sense--that is, covering both sexual intercourse and also actions [of touching] that are less than that. Those who don't say it carries all of its meanings and they are the majority say that the 'ayah points to sexual intercourse or to touching that is less than intercourse. If we say that it refers to sexual intercourse by consensus, then this nullifies the possibility of it referring to actions less than intercourse, as one [single] word could not be taken in its literal and figurative meaning [at the same time].
Those who say that what is less than sexual intercourse is included say so because it falls under the literal meaning of the verse. Those who differ do not take the word in its literal and figurative meaning at the same time.