ʿĀʾishah —may Allah be pleased with her— said: “The Sunnah for the one in iʿtikāf is that he does not visit the sick, nor attend a funeral, nor touch a woman or have intercourse with her, nor leave (the mosque) for any need except that which is unavoidable. There is no iʿtikāf without fasting, and there is no iʿtikāf except in a congregational mosque.”

Narrated by Abū Dāwūd (no. 2473), from the ḥadīth of ʿĀ’ishah — may Allah be pleased with her.
Authenticated in Ṣaḥīḥ Abī Dāwūd (no. 2135).

Brief Explanation of the Hadith

Iʿtikāf (spiritual retreat) is a noble act of worship through which the servant secludes himself with his Lord, devoting his time wholly to worship and detaching from worldly distractions. The Prophet — may Allah’s peace and blessings be upon him — used to observe it regularly during the last ten days of Ramaḍān.
In this ḥadīth, the Mother of the Believers ʿĀʾishah (may Allah be pleased with her) clarifies the principal manners and rulings that the one in iʿtikāf should observe—preserving the spirit and purpose of this act of devotion.
Her statement, “The Sunnah concerning the one in iʿtikāf…” means: the practice of the Prophet — may Allah’s peace and blessings be upon him — regarding iʿtikāf, and the manners and rulings that the one observing it should adhere to, is that he should not go out to visit the sick, attend a funeral, or engage in similar matters for which there is no necessity; for such actions contradict the purpose of iʿtikāf, which is to remain in the mosque and devote oneself exclusively to worship.
Likewise, it is not permissible for the one in iʿtikāf to have intercourse with his wife, nor to engage in any form of physical contact with desire short of intercourse; for iʿtikāf is an act of worship that requires detachment from worldly pleasures and desires. If he engages in intercourse, his iʿtikāf becomes invalid by the consensus of the scholars.
As for her statement, “There is no iʿtikāf without fasting,” it means that iʿtikāf is not complete except with fasting. However, this is not a condition for its validity but rather a reference to its perfection and greater reward. This is because the Prophet — may Allah’s peace and blessings be upon him — once observed iʿtikāf during the ten days of Shawwāl, and it was not reported that he was fasting at that time. Thus, fasting is not a requirement for the validity of iʿtikāf, though it is recommended due to the increase in reward and completion of virtue it brings.
And her statement, “There is no iʿtikāf except in a congregational mosque,” means that iʿtikāf is only valid when performed in a mosque, not in one’s home or a prayer area, since places other than the mosque are not designated for continuous acts of worship. Thus, performing iʿtikāf in a mosque is a condition for its validity, as Allah the Exalted says: “While you are staying in the mosques.” (Al-Baqarah 2:187)
This is a point of scholarly consensus. Some scholars, however, have permitted a woman to observe iʿtikāf in a part of her home as a concession.
The term “congregational” (jāmiʿ) indicates a mosque where the five daily prayers are regularly established. A place where congregational prayers are not held does not fully meet the definition of a mosque, and performing iʿtikāf there would require frequent departures to pray, which contradicts the purpose of iʿtikāf—remaining in the mosque and dedicating oneself wholly to worship.
The ḥadīth clarifies that iʿtikāf is a specific act of worship that requires remaining in the mosque and abstaining from distractions. The purpose is for the soul to be purified and dedicated sincerely to Allah Almighty during days that revive the heart and draw it closer to its Creator.