especially since, regarding intercourse during the daytime in Ramadan, there is the account of the man who had intercourse during the daytime in Ramadan and came asking [what he must do]. The Prophet ﷺ said to him: “Can you find a slave to set free?” (1) He did not say, “a believing slave,” although the context called for him to say so. For this reason, this view is very strong, and it is the position of Imam Abu Hanifah, Ibn al-Mundhir, and a group of scholars.
As for those who hold that faith is a condition, they cite the well-known principle: “An unrestricted expression is understood in light of a qualified expression when the ruling is the same.”
If this reasoning is not sound, then faith is a condition by analogy. That is, it may be argued: a slave whose manumission is required in order to absolve oneself of sin must be a believer, just like the slave whose manumission is required for the expiation of accidental killing.
However, this may be contested. As for the first argument—understanding an unrestricted expression in light of a qualified one—we may say that no such application exists here, because the rulings differ. In the expiation for killing, there is manumission and fasting, without feeding; whereas in the expiation for zihar and for intercourse during the daytime in Ramadan, there are manumission, fasting, and feeding. In the expiation for an oath, the difference is clear: it involves feeding, clothing, manumission, and fasting. Thus, it differs plainly from the expiation for killing.
Moreover, the causes differ. Although a difference in cause does not itself affect the matter, there must have been some factor that affected the ruling.
As for the argument from analogy, this analogy may be disallowed;