Ali bin Hujr bin Iyas bin Maqatil علي بن حجر بن إياس بن مقاتل · The Book on Fasting

"The Messenger of Allah vowed to stay away from his wives for a month, so he stayed in a loft for twenty-nine days. They said: 'O Messenger of Allah, your vow was for a month,' so he said: 'The month is twenty-nine (days).'"

"Kuraib informed me that Umm Al-Fadl bin Al-Harith sent him to Mu'awiyah in Ash-Sham. He said: 'So I arrived in Ash-Sham and finished her errand, and I saw the crescent of Ramadan while I was in Ash-Sham. We saw the crescent on the night of Friday. Then I arrived in Al-Madinah at the end of the month. Ibn Abbas was questioning me, then he mentioned the crescent and he said: "When did you see the crescent?" I said: "We saw…

the Prophet said: "Whoever is overcome by vomiting, then he is not required to make up (the fast), and whoever vomits on purpose, then he must make it up."

"A man asked Ali: "Which month do you order me to fast after the month of Ramadan?' He said to him, 'I have not heard anyone ask this except for a man whom I heard asking the Messenger of Allah while I was sitting with him. He said: "O Messenger of Allah! Which month do you order me to fast after the month of Ramadan?" He said: "If you will fast after the month of Ramadan, then fast Al-Muharram, for…

"Ibn Umar was asked about fasting (the Day of) Arafah (at Arafat). He said: 'I performed Hajj with the Prophet, and he did not fast it, and with Abu Bakr, and he did not fast it, and with Umar, and he did not fast it, and with Uthman, and he did not fast it. I do no fast it, nor order it nor forbid it."

Anas bin Malik was asked about the Prophet's fasting and he said: "He would fast during a month until we thought that he did not want to abstain from fasting during any of it. And, he would not fast during a month until we thought that he did not want to fast during any of it. (There was no time) that I wanted to see if he was performing Salat during the night, except that I would see him praying,…

The Prophet said: "When those who are not fasting eat in the presence of the fasting person, the angels send Salat upon him."

"We would menstruate during the time of the Messenger of Allah, then when we became pure we were ordered to make up the fasts but we were not ordered to make up the Salat."