Abu Ḥanifah.

A useful note: The author did not address the ruling on someone who breaks the fast of Ramadan deliberately and willfully—does he have to make it up or not? The more persuasive view is that he does not, and this is the choice of Shaykh al-Islam Ibn Taymiyyah, who said in al-Ikhtiyārāt, p. 65:

“Anyone who, without excuse, deliberately misses a fast or a prayer is not to make it up, and any such attempt would be invalid. The report that the Prophet ﷺ ordered the man who had intercourse during Ramadan to make up the fast is weak because al-Bukhārī and Muslim omitted it.”

This is also the view of Ibn Ḥazm, who traced it back to Abū Bakr al-Ṣiddīq, ʿUmar ibn al-Khaṭṭāb, ʿAlī ibn Abī Ṭālib, Ibn Masʿūd, and Abū Hurayrah; see al-Muḥallā 6/180–185.

Yet Ibn Taymiyyah’s reasoning—that the ḥadīth about the man who had intercourse in Ramadan is weak merely because the two Ṣaḥīḥs leave it out—carries no weight in my estimation. The two Shaykhs have omitted many a ḥadīth that is nonetheless authentic. In fact, as al-Ḥāfiẓ Ibn Ḥajar states, the report is sound when all its chains are combined, and one of those chains is sound though mursal, as I demonstrated in my notes on Ibn Taymiyyah’s Treatise on Fasting, pp. 25–27, and later in Irwāʾ al-Ghalīl 4/90–92. Making up the fast is part of the expiation required of that particular man, and the ruling does not extend to other deliberate breakers of the fast; thus Shaykh al-Islam’s position remains correct regarding them.

As for the prayer, the author likewise adopts this view, following Ibn Ḥazm. He had already summarized Ibn Ḥazm’s words in the section on “Prayer,” just before “Friday Prayer.” Consistency demanded that he choose the same opinion concerning fasting, for the evidence against making it up is identical in both cases—especially since it is also Ibn Ḥazm’s view. Ibn Ḥazm said:

“The proof is that the obligation to make up the fast for someone who deliberately vomits is authentically established from the Messenger of Allah ﷺ, as we have mentioned, whereas no text exists regarding invalidation of the fast through deliberate eating, drinking, or intercourse.”