Tafsir of Al-Fajr 89:3

By the dawn; And by the ten nights, And by the even and the odd. Concerning Al-Fajr, it is well known that it is the morning. This was said by Ali, Ibn Abbas, Ikrimah, Mujahid and As-Suddi. It has been reported from Masruq and Muhammad bin Ka`b that Al-Fajr refers to the day of Sacrifice (An-Nahr) in particular, and it is the last of the ten nights. The ten nights' refers to the (first) ten days of Dhul-Hijjah. This was said by Ibn `Abbas, Ibn Zubayr, Mujahid and others among the Salaf and the latter generations. It has been confirmed in Sahih Al-Bukhari from Ibn Abbas that the Prophet said,

ما من أيام العمل الصالح أحب إلى الله فيهن من هذه اﻻيام

There are no days in which righteous deeds are more beloved to Allah than these days. meaning the ten days of Dhul-Hijjah. They (the companions) said, "Not even fighting Jihad in the way of Allah'' He replied,

وﻻ الجهاد في سبيل الله إﻻ رجﻼ خرج بنفسه وماله ثم لم يرجع من ذلك بشيء

Not even Jihad in the way of Allah; except for a man who goes out (for Jihad) with his self and his wealth, and he does not return with any of that. Explanation of Night Concerning Allah's statement,

والليل إذا يسر