Anas ibn Malik reported: We used to prayer two cycles after the sun set before sunset prayer in the time of the Prophet, peace and blessings be upon him. It was said to him, “Did the Messenger of Allah pray both of them?” Anas said, “The Prophet saw us praying then but he did not command us, nor prohibit us from doing so.”
Source: Ṣaḥīḥ Muslim 836
Grade: Sahih (authentic) according to Muslim
عَنْ أَنَسِ بْنِ مَالِكٍ قَالَ وَكُنَّا نُصَلِّي عَلَى عَهْدِ النَّبِيِّ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ رَكْعَتَيْنِ بَعْدَ غُرُوبِ الشَّمْسِ قَبْلَ صَلَاةِ الْمَغْرِبِ فَقيل لَهُ أَكَانَ رَسُولُ اللهِ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ صَلَّاهُمَا قَالَ كَانَ يَرَانَا نُصَلِّيهِمَا فَلَمْ يَأْمُرْنَا وَلَمْ يَنْهَنَا
836 صحيح مسلم كتاب صلاة المسافرين وقصرها باب استحباب ركعتين قبل صلاة المغرب