What is the ruling on traveling to a specific mosque in a specific place and performing i'tikaf (spiritual retreat in the mosque) there for days?

Question : Yes. What happens with some people is that they designate a specific mosque in a specific place, travel to it, and stay in it for three days or more for the purpose of da'wah (calling others to Islam) and i'tikaf.

Answer : First, may Allah bless you, there is no prescribed i'tikaf except in the last ten days. The last ten days, yes; as for anything else, it is not permissible. It is not allowed. Second, intending this specific mosque for the purpose of i'tikaf is a mistake. However, choosing this mosque because people gather there and he wants to go to it to call them is permissible, because his travel now is not for the mosque itself, but for the place where the people gather. So if they gathered in a place other than this mosque, he would go there.