What is the ruling if a child intending to fast intends to fast overnight and then reaches puberty during the day?
General Chapter
Al-Mughni
Book of Fasting
Primary text
If a child intends to fast from the night and then reaches puberty during the day (by seminal emission or age), his fast is completed, and he owes no make-up. This is because the intention (Niyyah) for the Ramadan fast was established at night, fulfilling the requirement like an adult. It is permissible for the beginning of the fast to be voluntary and the remainder obligatory, analogous to someone vowing to complete a voluntary fast they have already begun.
Supporting text
Abu al-Khattab chose the view that make-up is necessary because it is a bodily act of worship, and reaching maturity during its performance necessitates its repetition, like prayer or Hajj if maturity occurs after the standing (wuquf). This is because the entire fast becomes obligatory upon maturity, and what preceded maturity was voluntary, thus not counting for the obligation.