What is the significance of Muḥarram and the day of ʿĀshūrāʾ?

"and finally they agreed on the year of the Hijra. Then they asked, Which month shall we begin with? They proposed Ramadan, but then decided on Muharram, as it is the month that people return from their pilgrimage, and it is a sacred month. Thus, they collectively agreed on Muharram. Ibn Abbas explained regarding the verse of Allah, By the dawn and the ten nights, that it refers to the dawn of Muharram, the first month of the year."

"marking the first commander in Islam. Al-Baihaqi narrated a similar account adding that when questioned about fighting in the sacred month they replied, we fight in the sacred month against those who expelled us from the sacred land. Another narration included Qutba ibn Malik between Sa'd and Ziyad which is considered more accurate. This hadith suggests that the first expedition was led by Abdullah ibn Josh al-Asadi contradicting ibn Ishaq's claim that the first banner was given to Ubaidah ibn al-Harith. Al-Waqidi also narrates that the first banner was given to Hamza ibn Abdul Mutalib and Allah knows best. Chapter the expedition of Abdullah ibn Josh. This expedition"

"celestial stars, dwelling in the highest stations. The virtuous days bearing hadith testimony of their nobility, merit, and the magnitude of reward in fasting them are, the day of Arafah, for those not performing Hajj, Ashura, the first ten days of Dhu al-Hijjah, the first ten days of Muharram, Rajab, and Shaban. Fasting the sacred months holds merit, which are Dhu al-Qidah, Dhu al-Hijjah, Muharram, and Rajab, one separate and three consecutive. In the year, beneficial times include the beginnings, middles, and ends of months, along with the white days, the 13th, 14th, and 15th. In the week, Mondays, Thursdays, and Fridays, offer"

"The Messenger of Allah, peace be upon him, would fast frequently in Sha'ban, almost as if it were Ramadan. It is narrated that the best fast after Ramadan is in the month of Allah, Muharram, as it marks the beginning of the year, and starting it with goodness is desirable. The Prophet, peace be upon him, said, "Fasting one day from a sacred month is better than fasting thirty days from another month, and fasting one day of Ramadan is better than fasting thirty days from a sacred month.""

"The hadith "Fasting one day in a sacred month is better than fasting thirty" is not found as such. However, in al-Tabarani's al-Mu'jam al-Saghir, there is a hadith from Ibn Abbas stating, "Whoever fasts one day of Muharram will receive the reward of thirty days." The hadith "Whoever fasts three days of a sacred month—Thursday, Friday, and Saturday" is recorded by Al-Azdi in the book of weak narrations from the narration of Anas."

"does the preparation of paradise for the devout exclude those with even the smallest amount of faith who have done no good at all. Some rely on fasting on the day of Ashura or the day of Arafa, claiming that fasting on Ashura atones for all the sins of the year, while fasting on Arafa offers additional reward. This deluded person does not realize that the fast of Ramadan, the five daily prayers hold greater significance than fasting on the day of Arafa and the day of Ashura."

"Qatada and others said that they boarded the ship on the tenth of the month of Rajab, traveled for 150 days, and settled on Mount Judi for a month. Their exit from the ship occurred on the day of Ashura in Muharram. Ibn Jarir reports a tradition that accords with this, stating that they observed fasting on that day. It is narrated from Abu Huraira that the Prophet peace and blessings be upon him passed by a group of Jews who were fasting on the day of Ashura."

"Qatada and others said they boarded the ship on the 10th day of Rajab and traveled for 150 days. It settled on Mount Judi for a month, and they departed on the day of Ashura in Muharram. Ibn Jarir narrated a tradition that they fasted on that day. Imam Ahmed reported from Abu Huraira that the prophet, peace and blessings be upon him, passed by some Jews fasting on the day of Ashura."

"about his identity and demise, and Allah knows best. Pharaoh and his troops perished on the day of Ashura. As Imam al-Bukhari mentioned in his Sahih, Ibn Abbas said, the Prophet, peace and blessings be upon him, arrived in Medina and found the Jews fasting on the day of Ashura. He asked, what is this day that you are fasting? They replied, this is the day Moses triumphed over Pharaoh. The Prophet, peace and blessings be upon him, said to his companions, you are more entitled to Moses than they are, so fast on this day. The origin of this hadith is found in the two Sahihs and other collections, and Allah knows best. Chapter on the affairs of the children of"

"into this matter regarding the hadith which says, Fasting on the day of Arafah expiates two years, and fasting on the day of Ashura expiates one year. They say, If it was his regular habit to fast on the day of Arafah, and he fasts it on the day of Ashura, how does it equate to expiating three years every year? Some responded by saying, that what surpasses expiation, grants increased ranks. What amazement, would that the servant's sins be expiated by these expiatory acts, altogether with some accumulating with others! This expiation is conditional on prerequisites, contingent upon all impediments being absent, so then expiation occurs. But a deed shrouded"