Is it permissible to perform i'tikaf in mosques and eat food therein for any number of days?

I'tikaf is an act of devotion and obedience, and its best time is the last ten days of Ramadan. It is permissible for the one performing i'tikaf to eat in the mosque, following the example of the Prophet, peace and blessings be upon him, who used to send food to the people of Suffah who lived in the mosque.