What is the requirement for vowing I'tikaf for a single day?
General Chapter
Al-Mughni
Book of I'tikaf
Primary text
If one vows I'tikaf for one day, separation is not permitted, and one must enter the place of I'tikaf before dawn and exit after sunset. The day's name intrinsically implies this sequential continuity, making it mandatory, similar to specifying two consecutive days.
Supporting text
Malik held that one must enter before sunset of the preceding night, similar to the ruling for a month, arguing that the night follows the day when continuity is implied. If one vows a single night, one must enter before sunset and exit after dawn, and separation is not permitted. If one states, 'I vow to perform I'tikaf for a day starting from this moment,' then I'tikaf is required from that moment until the equivalent time, including the subsequent night, as it is part of the entirety specified.