It is narrated from Sayyiduna Thawban (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "The fasts of Ramadan are equal to the fasts of ten months, and the fasts of six days are equal to the fasts of two months. Thus, the fasts of Ramadan and the six days after it will be as if one has fasted for the whole year."

Lady Aisha (may Allah be pleased with her) narrates that the Prophet Muhammad (peace be upon him) used to fast on Mondays and Thursdays.

Sayyiduna Abu Qatadah Ansari (may Allah be pleased with him) narrates that while we were sitting with the Messenger of Allah (peace be upon him), Sayyiduna Umar (may Allah be pleased with him) turned towards him and asked, "O Messenger of Allah, how is it to fast on Monday?" The Prophet (peace be upon him) said: "On this day I was born and on this day I will pass away." This hadith is from Qatadah. In the narration of Waki’, it is mentioned that a man asked the Messenger of Allah (peace be upon him), and there is no mention of Sayyiduna Umar (may Allah be pleased with him). And in it, it is stated: "On this day I was born, and on this day revelation was sent to me."

In the narration of Imam Shu’bah, it is mentioned that when Allah’s Messenger ( صلی اللہ علیہ وسلم ) was asked about his fasting, he became very displeased. And when he was asked about fasting on Mondays and Thursdays, he ( صلی اللہ علیہ وسلم ) said:“On Monday I was born, and on that day I was granted Prophethood,”or he said:“On that day revelation was sent down to me.”

Sayyiduna Usamah (may Allah be pleased with him) narrates that the Messenger of Allah (peace and blessings be upon him) used to fast on Mondays and Thursdays and would say: "On these two days, deeds are presented (before Allah, the Exalted)."

It is narrated from Sayyiduna Abu Hurairah (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "The deeds of people are presented (to Allah) twice every week, on Monday and Thursday. So, the forgiveness is granted to every believer, except for the person who has enmity or a quarrel with his brother. Allah Almighty says: 'Leave these two, or give them respite, until they return (to reconciliation).' Imam Abu Bakr (may Allah have mercy on him) says that this narration is reported as mawquf in Muwatta Imam Malik, while in Muwatta Ibn Wahb it is reported as marfu‘ and authentic."

Sayyiduna Abdullah bin Amr (may Allah be pleased with him) narrates that I came to the service of the Messenger of Allah (peace and blessings be upon him) and asked him about fasting. The Messenger of Allah (peace and blessings be upon him) said: "Fast one day in every month and you will receive the reward for the remaining days."

Sayyiduna Abu Dharr (may Allah be pleased with him) narrates that my beloved friend advised me regarding three things, which I will never leave, insha’Allah. The Prophet (peace and blessings be upon him) advised me to perform the Duha prayer, to offer Witr before sleeping, and to fast three days in every month.

Abu Hurairah (may Allah be pleased with him) reports that my close friend Abul Qasim (peace be upon him) advised me regarding three things: to fast three days every month, to perform Witr before sleeping, and to offer two units of Duha (forenoon) prayer.