Second Hadith
The Beloved Prophet şallAllāhu álayhi wa sallam also specified his own birthday in the same way. In a Hadīth narrated by Abu Qatada Ansarī rađiyAllāhu ánhu, he reports that Allah's Beloved Messenger şallAllāhu álayhi wa sallam was asked about fasting on Monday, whereupon he said:
It is (the day) when I was born and revelation was sent down to me.
Reference: Sahih Muslim, Bk 6, Number 2606.
This Hadīth is also reported in by Imām Abū Bakr al-Bayhaqī in his Sunan al-Kubra (Vol 4, Pg 300, Hadīth no. 8182, 8259); in the Sunan of Imām Nisa’ī and the Musnad of Imām Ahmad bin Hanbal.
It is clear from this Hadith that the Beloved Messenger şallAllāhu álayhi wa sallam was very happy about the day of his birth and so fasted out of gratitude. Fasting is a form of worship, so one can celebrate this day by any form of ibâdât. One can fast or hold gatherings or provide food to the poor, all being acts of worship.