Hadith 258

Bulugh al-Maram

Book 2: The Book of Prayer
وَعَنْهَا قَالَتْ : { لَمْ يَكُنْ اَلنَّبِيُّ ‏- صلى الله عليه وسلم ‏-عَلَى شَيْءٍ مِنْ اَلنَّوَافِلِ أَشَدَّ تَعَاهُدًا مِنْهُ عَلَى رَكْعَتَيْ اَلْفَجْرِ } مُتَّفَقٌ عَلَيْهِ .‏ 1‏
['Aishah (RA)]:

The Prophet (ﷺ) was more particular about offering the two (optional) Rak'at at dawn than he was about offering any of the other optional prayers. [Agreed upon].