Leaving the Masjid to Shave the Head and to take an Optional Bath

Q: It'kaaf-5: Will it be permissible for the person in I'tikaaf to leave the Masjid for reasons of personal hygiene such as having his hair shaved, taking a non-obligatory bath, etc?

Answer: It is wrong for the person in I'tikaaf to leave the Masjid to have his hair shaved or to take a bath that is not obligatory. Such acts will nullify the I'tikaaf. If the person's hair needs to be shaved, he may spread a sheet out in the Masjid and have it done, ensuring that no hair falls on to the Masjid's ground.' A bath that it non-obligatory does not fall within the ambit of necessities of the Shari'af (acts because of which it is permissible for him to l;eave the Masjid).

Fatawa Rahimiyyah vol.3