The meaning of the word عيد

It is derived from the verb عادَ يعودُ (to return).

Linguistically, ʿĪd (عيد) means something that returns repeatedly, such as ʿĪd al-Fiṭr and ʿĪd al-Aḍḥā, which return every year on specific days.

In Lisan al-Arab, Ibn al-A'rabi explains:

“سُمِّيَ العيدُ عيداً لأنه يعود كل سنة بفرحٍ مجدَّد”

“Eid was named Eid because it returns every year with renewed happiness.”

It was narrated that Anas ibn Malik (رضي الله عنه) said:

“The people of the Jāhiliyyah had two days each year when they would play. When the Messenger of Allah (ﷺ) came to Al-Madīnah he said:

‘You had two days when you would play, but Allah has given the Muslims something better than them: the day of Al-Fiṭr and the day of Al-Aḍḥā.’”

(Sunan an-Nasa'i, 1556)

Based on the linguistic meaning of ʿĪd, and this and similar aḥādīth, Ahlul Ḥadīth scholars have ruled that it is impermissible for Muslims to observe other recurring celebrations such as birthdays or anniversaries.