The intention is in the heart, and does not have to be uttered with the tongue. The one who slept at night without having had the intention to fast and woke up after the dawn is obligated to abstain from whatever a fasting person would abstain and then fast a make up for that day. If the menstrual or postpartum bleeding of a woman stopped at night, then she must intend to fast the following day. The purificatory bath is not required to start fasting, but rather to start praying.

The intention for any obligatory fasting during Ramadan, must take place the night before the fast. However, for the one who is fasting an optional fast, it is not a condition that he must intend to do so the preceding night.