What really happened on 10th Muharram in Muslim history?

"The 10th day of Muharram, known as Yawm Al-‘Ashura, is the most significant day of this month.
The Prophet (SAW) said: “Fasting on the Day of ‘Ashura is an expiation of sins for the previous year”. Many events are attributed to this date such as that the Prophet Adam was born and his repentance was accepted on this day, the Prophet Abraham was saved from the Fire, the Prophet Ishmael was delivered from the Sacrifice, the Prophet Joseph was reunited with his father, the Prophet Job was cured of his illness and the Prophet Solomon was ordained as king on this day, but these assertions are not backed by accurate historical evidences.

Ibn Abbas relates that when Prophet Muhammad (SAW) came to Madinah, he found the Jews fasting on the Day of ‘Ashura. When asked for the reason of their fasting, they replied that it was the day when Allah Ta‘ala saved the Prophet Moses and the Children of Israel from their enemies. Moses fasted to thank Allah and they fasted in emulation of him. So the Prophet (SAW) said “We have more of a right to Moses than you” and so he ordered the Muslims to fast on that day. This fast was later abrogated with the fast of Ramadan substituted in its place but it was kept as an optional recommended fast. However, in order not to follow the Jews, the Prophet encouraged Muslims by saying: “Observe the fast of ‘Ashura and differ from the Jews by fasting a day before it or after it”.

Martyrdom of Imam Husayn
The Prophet’s younger grandson Husayn was tragically martyred on 10th Muharram 61 AH/ 680 CE. As a result, the Shi‘ites commemorate Husayn’s martyrdom and give prominence to this day.
But it must be remembered that ‘Ashura was given significance by the Prophet himself- hence it is pointless to claim that this day is significant due to Husayn’s martyrdom which happened three decades after the Prophet’s death. However, the heroic martyrdom of Imam Husayn demonstrates to Muslims the need to uphold truth and justice and to fight against tyranny and evil and they should be prepared to give their lives in a similar cause if the need arises. Such situations are all too common in our own times when Muslims are being persecuted for their faith in many parts of the world.''

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