it is a voluntary fast, and if he exits it, he is not obligated to make it up, just as if he believed it was from Ramadan but it turned out to be from Sha'ban or Shawwal. As for the report they cite, Abu Dawud said: It is not established. Al-Tirmidhi said: There is some criticism regarding it. Al-Jawzjani and others weakened it. Furthermore, it is interpreted as being for recommendation (istihbab). Once this is established, it is recommended for him to complete it, and if he exits it, it is recommended to make it up, in order to avoid the disagreement and to act upon the report they narrated.
Section: The rule for other acts of supererogatory worship (nawafil) is the same as the rule for fasting, in that they do not become mandatory upon commencing them, nor is it mandatory to make them up if one exits them, with the exception of Hajj and Umrah. They differ from all other acts of worship in this regard due to the confirmation of their ihram (state of consecration), and one does not exit them by invalidating them. If one believed them to be mandatory while they were not, one would not be permitted to exit them. It has been narrated from Ahmad regarding prayer that which indicates it becomes mandatory upon commencing it, as al-Athram said: I said to Abu Abd Allah: "If a man begins his day fasting voluntarily, does he have the choice (to break it)? And if a man enters into prayer, is he permitted to interrupt it?" He replied: "Prayer is more severe; as for prayer, he should not interrupt it." It was said to him: "If he interrupts it, does he make it up?" He said: "If he makes it up, there is no disagreement regarding that." Abu Ishaq al-Jawzjani leaned towards this opinion and said: "Prayer has an ihram and an ihlal (state of sanctity and exiting it), so it becomes mandatory upon commencing it, like Hajj." Most of our companions maintain that it does not become mandatory either. This is the opinion of Ibn Abbas, because what is permitted to be abandoned entirely is permitted to be abandoned in part, like charity, and Hajj and Umrah differ from other acts.
Section: Whoever enters into a mandatory act, such as making up a day of Ramadan, a specific or absolute vow, or a fast of expiation, it is not permitted for him to exit it. This is because, in the case of a specific obligation, entering it was mandatory, and in the case of a non-specific one, it becomes specific by his entering into it, so it becomes equivalent to a specific obligatory act. There is no disagreement regarding this, praise be to Allah.
511 - Issue; He said: (And when the boy reaches ten years of age and has the capacity to fast, he is to be held to it.)
Meaning that he is obligated to fast; he is commanded to do so and disciplined for abandoning it, so that he may train for it and become accustomed to it, just as
