Sahih al-Bukhari 561

Arabic

حَدَّثَنَا الْمَكِّيُّ بْنُ إِبْرَاهِيمَ، قَالَ حَدَّثَنَا يَزِيدُ بْنُ أَبِي عُبَيْدٍ، عَنْ سَلَمَةَ، قَالَ كُنَّا نُصَلِّي مَعَ النَّبِيِّ صلى الله عليه وسلم الْمَغْرِبَ إِذَا تَوَارَتْ بِالْحِجَابِ‏.‏

English translation

Narrated Salama:We used to pray the Maghrib prayer with the Prophet (ﷺ) when the sun disappeared from the horizon

Reference: Sahih al-Bukhari 561, Book of Times of the Prayers. English translation by Dr. Muhammad Muhsin Khan.