to announce it. Moreover, religious obligation depends on knowledge: if knowledge of it is not possible, fasting that day is not obligatory. Requiring a missed fast to be made up when its omission involved no negligence requires evidence.

Furthermore, if making up the fast were obligatory or recommended when news of a sighting in a distant place, or by a small number of people, arrived during the month, then fasting on the day of doubt would be recommended even under clear skies—indeed, fasting on the thirtieth day would be recommended in all circumstances. This is because a few people, or someone far away, might report during the month that they had sighted the crescent; fasting as a precaution would therefore be recommended. Whenever something may be obligatory under the Sharia, taking the precaution of performing it is prescribed. Since such precautionary observance is not prescribed here, we know conclusively that no obligation arises while the observer is distant or unknown. Rather, the observer must be nearby and publicly known, so that his sighting constitutes an announcement making the crescent’s appearance known.

Those who do not take precautions when the sky is overcast may invoke this argument. The response, however, is that its rising in this situation is an evident or comparable instance; it is only the obstruction that prevents sighting. This is like people being in a cave or an underground chamber on the thirtieth night, unable to look for the crescent.

Furthermore, the fundamental reasoning of those who do not require the intention to fast to be formed during the night is that fasting on the day of doubt suffices. News of a sighting often arrives before noon, as with the day of ʿĀshūrāʾ. Requiring that day to be made up entails hardship, because such situations occur frequently, while an obligation to make it up was not widely known among the early generations. The answer is that an obligation to abstain from whatever breaks the fast does not necessarily entail an obligation to make up the day.