I say, and with God's success: It is not permissible, and if he goes out for that purpose, it invalidates his I'tikaf; because he can fulfill these needs in the mosque, as they do not contradict being in the mosque. Refer to: Al-Waqayah p. 245, Al-Mabsut 3: 118, and Al-Tabyin 1: 351, and God knows best.