وَلِمُسْلِمٍ مِنْ حَدِيثِ أَبِي مُوسَى: «فَأَقَامَ اَلْفَجْرَ حِينَ اِنْشَقَّ اَلْفَجْرُ، وَالنَّاسُ لَا يَكَادُ يَعْرِفُ بَعْضُهُمْ بَعْضًا»
He (sallallahu alayhi wa sallam) offered the Fajr prayer at daybreak when the people could hardly recognize one another.
Bulugh al-Maram 185, Book 2, The Book of Prayer, Hadith 6. 1 min read