سنن النسائي

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.