during his i'tikaf, his stipulation would not be valid, because it permits what Allah has prohibited. Every condition that permits what Allah has prohibited is invalid, for the Prophet said: “Every condition that is not found in the Book of Allah is invalid, even if there are a hundred conditions.” (1)
It is recommended that he occupy himself with acts of devotion and avoid that which does not concern him.
His statement, “It is recommended that he occupy himself with acts of devotion,” means that it is recommended for the person observing i'tikaf to devote himself to acts of worship, such as reciting the Quran, remembrance of Allah, voluntary prayer at times when prayer is not prohibited, and the like. This is better than attending circles of knowledge—unless such circles are rare and he would not have the opportunity to attend them at another time. In that case, we may say that seeking knowledge is better than occupying oneself with individual acts of worship, so he should attend them, for this does not distract from the purpose of i'tikaf.
His statement, “and avoid that which does not concern him,” means that it is recommended for the person observing i'tikaf to avoid whatever does not concern him, whether words, actions, or anything else. This is a sunnah for him and for others as well. The Prophet said: “Part of a person’s excellence in Islam is leaving aside what does not concern him.” (2) This is part of a person’s excellence in Islam, good manners, and peace of mind: that he leave aside what does not concern him. As for investigating matters that do not concern him, this will only weary him.
Likewise, if he follows people’s affairs in matters that do not concern him, then part of a person’s excellence in Islam, good manners, and peace of mind is that he leave aside what does not concern him. For this reason,