Musannaf Ibn Abi Shaybah

Ibrahim narrates that Hazrat Hudhaifa (may Allah be pleased with him) once came to Hazrat Abdullah and said to him, "Are you not amazed at those people who are sitting in i'tikaf in the mosque between your house and the house of Ash'ari?" Hazrat Abdullah replied, "Perhaps they are right and you are mistaken." Hazrat Hudhaifa (may Allah be pleased with him) said, "Do you not know that i'tikaf is only to be observed in three mosques: the Sacred Mosque (Masjid al-Haram), the Aqsa Mosque, and the Prophet's Mosque (peace and blessings be upon him)? In my opinion, sitting in i'tikaf in the mosque where those people are sitting is the same as sitting in i'tikaf in the marketplace."

Hazrat Ali (may Allah be pleased with him) said that I'tikaf is only observed in the central mosque of a city.

Hazrat Shaddad bin Azma’ reports that a man sat for i’tikaf in the Grand Mosque and pitched a tent. People forbade him from doing so. This news reached Hazrat Abdullah bin Mas’ud (may Allah be pleased with him), so he sent a man who made the people stay away from him and instructed them to treat him kindly.

Hazrat Saeed bin Musayyib says that I'tikaf is permissible only in the mosque of the Holy Prophet (peace and blessings be upon him).

Hazrat Zuhri says that I'tikaf can only be observed in a congregational mosque.

Hazrat Sha’bah states that I asked Hazrat Hakam and Hazrat Hammad about I’tikaf, so they said that I’tikaf can only be observed in a congregational mosque.

Hazrat Abu Ja'far says that I'tikaf can only be observed in a congregational mosque.

Hazrat Urwah says that I'tikaf can only be observed in a congregational mosque.