(18) باب وَقْتِ الْمَغْرِبِ
Narrated Jabir bin `Abdullah:
The Prophet (ﷺ) used to pray the Zuhr at midday, and the `Asr at a time when the sun was still bright, the Maghrib after sunset (at its stated time) and the `Isha at a variable time. Whenever he saw the people assembled (for `Isha' prayer) he would pray earlier and if the people delayed, he would delay the prayer. And they or the Prophet (ﷺ) used to offer the Fajr Prayers when it still dark.
Reference: Sahih al-Bukhari 560
In-book reference: Book 9, Hadith 37
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 1, Book 10, Hadith 535