1616. If a person who is fasting intentionally immerses his entire head under water, his fast will be invalidated even if the rest of his body remains outside the water. However, if the entire body is immersed, but a part of the head remains outside, his fast will not be invalidated.
1617. If a person immerses a part of his head under the water in an instance, and then immerses another part of his head in another instance, his fast will not be invalidated.
1618. If a person doubts whether his entire head was immersed or not, his fast will remain in order. However, if he immerses his head under water with the intention of immersing his entire head, but later doubts whether he immersed it entirely or not, his fast will be invalidated. However he will not have to pay its kaffÁrah.
1619. If the entire head is immersed under water, but a part of the hair remains outside the water, the fast is invalidated.
1620. Immersing the head under a liquid other than water, such as milk or muÃÁf water, does not invalidate the fast. Obligatory precaution dictates that one should avoid immersing his head under rose-water.
1621. If a person involuntarily falls into the water, causing his entire head to be immersed, his fast will not be invalidated. The same will apply for someone who forgets that he is fasting, and immerses his head under water.
1622. If a person feels that his head will not get immersed under water, and therefore jumps into the water, and his head does in fact get entirely immersed, it will not harm his fast.
1623. If a person forgets that he is fasting and immerses his head under water, but realizes that he is fasting whilst he is under the water, he should immediately remove his head from the water. If he fails to do so, his fast will be invalidated.
The same will apply to a person whose head is forcefully immersed under water, but then regains his volition whilst his head is in the water.
1624. If a person forgets that he is fasting, and immerses his head under the water with the intention of performing ghusl, both his ghusl and fast will be in order.
1625. If a person knows that he is fasting, and intentionally immerses his head under water with the intention of performing ghusl, should his fast be the fast of the month of Ramadan, both his fast and ghusl will be void. The same will apply to the qaÃÁ of the fast of the month of Ramadan that a person is fasting for himself, if the aforementioned scenario occurs after midday, based on precaution. However, if the fast is a recommended one, or another obligatory fast—be it a date-specific fast, such fasting to fulfill a vow to fast on a particular day, or a non-specific fast, such as the fast of a kaffÁrah—his ghusl will be in order, but his fast will be voided.
1626. If a person immerses his head under water in order to save a drowning person, although saving the drowning person is obligatory, his fast will be invalidated nonetheless.
