Imām Bukhārī narrates: Al-Makkī ibn Ibrāhīm narrated to us, he said: Yazīd ibn Abī 'Ubaid narrated to us, from Salamah, may Allāh be pleased with him, he narrated:
We used to pray the Maghrib prayer with the Prophet ﷺ at the time when the sun disappeared behind the veil.
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.
Reference: Sahih Al Bukhari 561