Is it permissible to perform i'tikaf (spiritual retreat in the mosque) in a room inside the mosque?

The questioner : We have decided years ago that i'tikaf is not valid in it.

The Shaykh : Yes, we decided. How many years ago?

The questioner : Perhaps when we were in the book on fasting, in the chapter on i'tikaf.

The Shaykh : There is a possibility here. One who looks at the general statements of the jurists says that it is part of the mosque, because he says that the room or chamber surrounded by the mosque's wall is part of the mosque. Be patient, men. And one who looks at it as having been built not as part of the mosque, but as a chamber for the imam, sees it as being like the houses of the Messenger (peace and blessings be upon him). The doors of the Messenger's (peace and blessings be upon him) houses opened onto the mosque, and yet they were houses, not places the Messenger (peace and blessings be upon him) would go out to. So the precaution is that the one performing i'tikaf should not be in it. But the custom of the people among us now is that the chambers in the mosques are considered part of the mosque. Yes, indeed.