Hadith.2096 - It is narrated by Abu Ayyub, from Muhammad ibn Muslim, from Abu Ja'far (as), who said
"If a man begins i'tikaf for one day and has not made any stipulation, he is allowed to leave and break his i'tikaf. However, if he has completed two days without making a stipulation, he is not permitted to break his i'tikaf until three days have been completed."