(6) باب فِي وَقْتِ الْمَغْرِبِ
Salamah b. al-Akwa' said:
The Prophet (ﷺ) used to say the Maghrib prayer immediately after the sun had set when its upper side would disappear.
Reference: Sunan Abi Dawud 417
In-book reference: Book 2, Hadith 27
English translation: Book 2, Hadith 417