Al-Muharram is the first month of the Islamic lunar calendar. It has a special significance for Muslims and is considered one of the four forbidden months, as stated in the Qur'an: Indeed, the number of months with Allāh is twelve [lunar] months in the register of Allāh [from] the day He created the heavens and the earth; of these, four are sacred.1 That is the correct religion [i.e., way], so do not wrong yourselves during them... 9:36.

Ali ibn Abu Talha reports that ibn Abbas said about the words of Allah: “Indeed, the number of months with Allah ...” - i.e. do not do wrong in all the months, and then Allah marked four months, made them forbidden and exalted their holiness, so that the sin done in them increases as well as the good deed done.

You can keep additional fasts for the sake of Allah, as the prophet Muhammad, peace and blessings be upon him, said: “The best fast after the month of Ramadan is fasting in the month of Allah, which you call al-Muharram” (Sahih Muslim).

Also in this month, on the 10th day, the holiday "Day of 'Ashura" is celebrated, on which it is sunnah to fast. You can read about this holiday in the next section.