كتاب المواقيت
6  
The Book of the Times (of Prayer)
It was narrated that Muhammad bin 'Amr bin Hasan said:
"Al-Hajjaj arrived, and we asked Jabir bin 'Abdullah, who said: 'The Messenger of Allah (ﷺ) prayed Zuhr at the time of intense heat, [1] and 'Asr when the sun was white and clear, and Maghrib when the sun set, and with 'Isha' it would depend - if he saw that the people had gathered, he would pray early, and if he saw that they had not come yet, he would delay it.'" [1] Meaning, at the earliest time.
أَخْبَرَنَا عَمْرُو بْنُ عَلِيٍّ، وَمُحَمَّدُ بْنُ بَشَّارٍ، قَالاَ حَدَّثَنَا مُحَمَّدٌ، قَالَ حَدَّثَنَا شُعْبَةُ، عَنْ سَعْدِ بْنِ إِبْرَاهِيمَ، عَنْ مُحَمَّدِ بْنِ عَمْرِو بْنِ حَسَنٍ، قَالَ قَدِمَ الْحَجَّاجُ فَسَأَلْنَا جَابِرَ بْنَ عَبْدِ اللَّهِ قَالَ كَانَ رَسُولُ اللَّهِ صلى الله عليه وسلم يُصَلِّي الظُّهْرَ بِالْهَاجِرَةِ وَالْعَصْرَ وَالشَّمْسُ بَيْضَاءُ نَقِيَّةٌ وَالْمَغْرِبَ إِذَا وَجَبَتِ الشَّمْسُ وَالْعِشَاءَ أَحْيَانًا كَانَ إِذَا رَآهُمْ قَدِ اجْتَمَعُوا عَجَّلَ وَإِذَا رَآهُمْ قَدْ أَبْطَئُوا أَخَّرَ ‏.‏
Grade: Sahih (Darussalam)
Sunnah.com reference : Book 6, Hadith 34
English translation : Vol. 1, Book 6, Hadith 528
Arabic reference : Book 6, Hadith 532