حَدَّثَنَا الْحَسَنُ بْنُ بِشْرٍ، حَدَّثَنَا الْمُعَافَى، عَنْ عُثْمَانَ بْنِ الأَسْوَدِ، عَنِ ابْنِ أَبِي مُلَيْكَةَ، قَالَ أَوْتَرَ مُعَاوِيَةُ بَعْدَ الْعِشَاءِ بِرَكْعَةٍ وَعِنْدَهُ مَوْلًى لاِبْنِ عَبَّاسٍ، فَأَتَى ابْنَ عَبَّاسٍ فَقَالَ دَعْهُ، فَإِنَّهُ صَحِبَ رَسُولَ اللَّهِ صلى الله عليه وسلم‏.‏
Translation
Narrated Humran bin Aban

Muawiya said (to the people), "You offer a prayer which we, who were the companions of the Prophet (ﷺ) never saw the Prophet (ﷺ) offering, and he forbade its offering," i.e. the two rak`at after the compulsory `Asr prayer.