Mughith bin Sumayy reported,

I prayed the dawn prayer with Abdullah bin Zubayr while it was still dark. When he gave the closing salutation, I turned to Ibn Umar and asked, "What prayer is this?"He replied, "This was our prayer with the Messenger of Allah ﷺ, Abu Bakr, and Umar. When Umar was stabbed, Uthman delayed it until daylight had spread."

Azami 1782

Sahih

عن مغيث بن سمي قال

صليت مع عبد الله بن الزبير الصبح بغلس، فلما سلم أقبلت على ابن عمر، فقلت: ما هذه الصلاة؟ قال: هذه صلاتنا كانت مع رسول الله ﷺ وأبي بكر وعمر، فلما طعن عمر أسفر بها عثمان.

الأعظمي 1782صحيح
Contents
Reference
Commentary
Ayat
Collection
Jami al-Kamil
Book
Prayer
Chapter
Prayer times
Section
Recommendation of praying Fajr early and performing it in the darkness before dawn
Numbering
Jami al-Kamil 1782 (2nd edition)