Kharjh bin 'Abdullah خارجة بن عبد الله بن سليمان · The Book of the Times (of Prayer)

"Al-Hajjaj arrived, and we asked Jabir bin 'Abdullah, who said: 'The Messenger of Allah (ﷺ) prayed Zuhr at the time of intense heat, 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.'" Meaning, at the earliest time.