When the Messenger of Allah—may peace and blessings be upon him—arrived in Madinah, he found that the people had two days on which they engaged in play. He said, “Allah has replaced them for you with two days that are better: the Day of Sacrifice (ʿId al-Aḍḥā) and the Day of Breaking the Fast (ʿId al-Fiṭr).” 1 It is said that the two earlier occasions were Nayrūz and Mahrajān.
He substituted them because every festival that people observe is, at its origin, a celebration of certain religious rites, a tribute to the leaders of a particular creed, or something akin to that. The Prophet ﷺ feared that if he left them to their inherited custom, it would amount to reviving the rites of paganism or promoting the practices of their forefathers. Therefore he replaced those occasions with two days that proclaim the rites of the upright monotheistic faith, while coupling the wearing of finery with the remembrance of Allah and various doors of obedience—so that the Muslims’ gathering would not be pure amusement and so that no assembly of theirs would be devoid of exalting the word of Allah.
The first of the two is the day on which they break their fast and discharge a particular form of their zakat. Natural joy is thus achieved: they are relieved of what had been arduous for them, and the poor receive charity. Rational joy is likewise attained: they rejoice that Allah enabled them to fulfill what He made obligatory upon them and that He has preserved their families and children for yet another year.