Ibn Abbas explained the following Qur'anic verse: "O ye who believe! fasting is prescribed for you as it was prescribed for those before you" During the lifetime of the Prophet (ﷺ), when the people offered night prayer, they were asked to abstain from food and drink and (intercourse with) women, they kept fast till the next night. A man betrayed himself and had intercourse with his wife after he had offered the night prayer, and he did not break his fast. So Allah, the Exalted, intended to make it (fasting) easy for those who survived, thus providing a concession and utility. Allah, the Glorified, said: "Allah knoweth what ye used to do secretly among yourselves." By this Allah benefited the people and provided concession and ease to them.

Al Bara’ (bin Azib) said “When a man fasted and slept, he could not eat till (another nigh) like it.” Sarmah bin Qais Al Ansari came to his wife while he was fasting and asked her Do you have something (to eat)? She replied “No”. Let me go and seek something for you. So, she went out and sleep overcame him. She came (back) and said (to him).You are deprived (of food). He fainted before noon. He used to work all day long at his land. This was mentioned to the Prophet (ﷺ). So the following verse was revealed. “Permitted to you on the nights of the fasts, is the approach to your wives. They are your garments and ye are their garments. Allah knoweth what yes used to do secretly amongst yourselves. But he turned to you and forgave you. So now associate with them and seek what Allaah hath ordained for you. And eat and drink until the white thread of dawn appears to you. He recited up to the words “of dawn”.

Salamah bin Al Akwa said “After the revelation of the verse “For those who can do it(with hardship) is a ransom, the feeding of one, that is indigent, is one of us intended to leave fast and pay ransom, he could do so.” until the verse following it was revealed and abrogated the (previous) verse.”

Ibn ‘Abbas explain the Qur’anic verse “For those who can do it(with hardship) is a ransom, the feeding of one, that is indigent” said “If one of them wished to pay ransom by providing food to an indigent person he could pay ransom.. Thus, his fast was complete. Allaah, the Exalted pronounced “But he that will give more of his own free will, it is better for him”. Again he pronounced “So every one of you who is present (at his home) during that month should spend it in fasting.” But, if anyone is ill or on a journey the prescribed period (should be made up) by days later.

Ibn ‘Abbas said “The verse concerning the payment of ransom stands valid for pregnant and sucking woman.”

Explaining the verse; "For those who can do it (with hard-ship) is a ransom, the feeding of one, that is indigent," he said: This was a concession granted to the aged man and woman who were able to keep fast; they were allowed to leave the fast and instead feed an indigent person for each fast; (and a concession) to pregnant and suckling woman when they apprehended harm (to themselves).

The Prophet (ﷺ) said: The month consists of twenty-nine days, but do not fast till you sight it (the moon) and do not break your fast till you sight it. If the weather is cloudy, calculate it thirty days. When the twenty-ninth of Sha'ban came, Ibn Umar would send someone (who tried) to sight the moon for him. If it was sighted, then well and good; in case it was not sighted, and there was no cloud and dust before him (on the horizon), he would not keep fast the next day. If there appeared (on the horizon) before him cloud or dust, he would fast the following day. Ibn Umar would end his fasting alone with the people, and did not follow this calculation.

Ibn ‘Umar reported the Apostle of Allaah(ﷺ) as saying “The month consists of twenty nine days, but do not fast till you sight it (the moon) and do not break your fast till you sight it. If the weather is cloudy, calculate it thirty days. When the twenty-ninth of Sha’ban came, Ibn ‘Umar would send someone (who tried) to sight the moon for him. If it was sighted then well and good, in case it was not sighted and there was no cloud and dust before him (on the horizon) he would not keep fast the next day. If there appeared (on the horizon) before him cloud or dust, he would fast the following day. Ibn ‘Umar would end his fasting alone with the people and did not follow this calculation.”

'Umar b. 'Abd al-'Aziz wrote (a letter) to the people of Basrah: It has reached us from the Messenger of Allah (ﷺ), like the tradition narrated by Ibn 'Umar from the Prophet (ﷺ). This version adds: The best calculation is that when we sight the moon of Sha'ban on such-and-such date, fasting will being on such-and-such dates, Allah willing, except they they sight the moon before that (date).

We kept fast for twenty-nine days along with the Prophet (ﷺ) more often than we kept fast for thirty days.

The Prophet (ﷺ) as saying: The two months of 'Id (festival), Ramadan and Dhu al-Hijjah, are not defective.

The Prophet (ﷺ) said: The end of Ramadan is on the day when you end it, and the 'Id (festival) of sacrifice is on the day when you sacrifice. The whole of Arafah is the place of staying, and the whole of Mina is the place of sacrifice, and all the roads of Mecca are the place of sacrifice, and the whole of Muzdalifah is the place of staying.

The Messenger of Allah (ﷺ) used to count the days in Sha'ban in a manner he did not count any other month; then he fasted when he sighted the new moon of Ramadan; but if the weather was cloudy he counted thirty days and then fasted.

The Prophet (ﷺ) said: Do not fast (for Ramadan) before the coming of the month until you sight the moon or complete the number (of thirty days); then fast until you sight the moon or complete the number (of thirty days).

The Prophet (ﷺ) said: Do not fast one day or two days just before Ramadan except in the case of a man who has been in the habit or observing a fast (on that day); and do not fast until you sight it (the moon). Then fast until you sight it. If a cloud appears on that day (i.e. 29th of Ramadan) then complete the number thirty (days) and then end the fasting: a month consists of twenty-nine days.

The Messenger of Allah (ﷺ) asked a man: Did you fast the last day of Sha'ban ? He replied: No. He said: If you did not observe a fast, you must fast for a day. One of the two narrators said: For two days.

AbulAzhar al-Mughirah ibn Farwah said: Mu'awiyah stood among the people at Dayr Mustahill lying at the gate of Hims. He said: O people, we sighted the moon on such-and-such day. We shall fast in advance. Anyone who likes to do so may do it. Malik ibn Hubayrah as-Saba'i stood up and asked: Mu'awiyah, did you hear the Messenger of Allah (ﷺ) say something (about this matter), or is this something on the basis of your opinion? He replied: I heard the Messenger of Allah (ﷺ) as saying: Fast the month (in the beginning) and in the last.

I heard Abu 'Amr al-Auza'i say: The word sirrahu means beginning of the month.

On the authority of Abu Mushir. He said: Sa'id, that is, Ibn 'Abd al-'Aziz said: The meaning of the word sirraha is "in the beginning of it (the month)"