Bulugh al-Maram

"None of you should fast a day or two before the (beginning of the) month of Ramadan, unless it is a day on which one is in the habit of fasting (i.e. voluntary fasting that coincides with that day)." Agreed upon.

Ammar bin Yasir (RAA) narrated, "Whoever fasts the day of doubt he has then disobeyed Abu al-Qasim (the Prophet).' Related by the five Imams, and Ibn Khuzaimah and Ibn Hibban graded it as Sahih

Ibn 'Umar (RAA) narrated, "I heard the Messenger of Allah (ﷺ) say, "Start fasting after you have seen it (i.e. the new crescent) and end the fast (at the end of the month) when you see it. If it is overcast and cannot be seen, then estimate its sighting (i.e. presume that Sha"ban lasted for thirty days)." Agreed upon. Muslim narrated, "If it is too overcast to be seen then presume that it (Sha'ban) lasted for thirty days."In another narration by al-Bukhari, "wait, until thirty days of it (Sha'ban) have passed."

Al-Bukhari reported on the authority of Abu Hurairah, "Complete the days of Sha'ban as thirty days."

Ibn 'Umar (RAA) narrated, "The people were trying to sight the new moon (of Ramadan.) and when I reported to the Messenger of Allah (ﷺ) that I had seen it, he fasted and commanded people to fast.' Related by Abu Dawud, and Al-Hakim and Ibn Hibban graded it as Sahih.

Ibn "Abbas (RAA) narrated, "A Bedouin came to the Prophet and said, "I have sighted the crescent (of Ramadan). He then said to him, "Do you testify that there is none worthy of worship but Allah?" The Bedouin said, "Yes.' He asked him again, "Do you testify that Muhammad is the Messenger of Allah (ﷺ)?" The man replied, "Yes.' The Messenger of Allah (ﷺ) there upon said, "O Bilal! Announce to the people to (start) fasting tomorrow." Related by the five Imams. Ibn Khuzaimah and Ibn Hibban graded it as Sahih. An-Nasa'i said that it is most probably Mursal (a Hadith in which the link between the Successor (Tabi'i) and the Prophet (ﷺ) is missing.

"Whoever does not form his intention to fast before to fajr, his fasting will not be accepted." Related by the five Imams, but At-Tirmidhi and An-Nasa'i consider it to be related by Hafsah and not connected to the Prophet (ﷺ). Imam Ad-Daraqutni transmitted, "No fasting is accepted for one who does not form the intention (to fast) the night before."

A'isha (RAA) narrated, "One day the Messenger of Allah (ﷺ) entered my house and said, "ls there anything here (to eat)?" I said, "NO,' He said, "I shall then be fasting (today)." Then he came to us another day and we said to him, 'Someone has offered us some hais as a gift.' He then said, "Show it to me. I had been fasting since this morning, "and he ate from it ( as it was a voluntary fast and not during the obligatory fasting of Ramadan). Related by Muslim.

"People will always be fine (on the right path, or following the Sunnah) as long as they hasten to break their fast (in Ramadan)." Agreed upon.

"Allah, the Most Exalted said: "Those among My servants, who hasten to break their fast, are the most beloved (or dearest)to Me." Related by At-Tirmidhi.