Sahih al-Bukhari, Hadith 3766 ⓘ
Narrated Humran bin Aban: Muawiya said (to the people), "You offer a prayer which we, who were the companions of the Prophet never saw the Prophet offering, and he forbade its offering," i.e. the two rak`at after the compulsory `Asr prayer.
حَدَّثَنِي عَمْرُو بْنُ عَبَّاسٍ، حَدَّثَنَا مُحَمَّدُ بْنُ جَعْفَرٍ، حَدَّثَنَا شُعْبَةُ، عَنْ أَبِي التَّيَّاحِ، قَالَ سَمِعْتُ حُمْرَانَ بْنَ أَبَانَ، عَنْ مُعَاوِيَةَ ـ رضى الله عنه ـ قَالَ إِنَّكُمْ لَتُصَلُّونَ صَلاَةً لَقَدْ صَحِبْنَا النَّبِيَّ صلى الله عليه وسلم فَمَا رَأَيْنَاهُ يُصَلِّيهَا، وَلَقَدْ نَهَى عَنْهُمَا، يَعْنِي الرَّكْعَتَيْنِ بَعْدَ الْعَصْرِ.
also referenced under: Book 62, Hadith 113 (In-Book) & Volume 5, Book 57, Hadith 110 (USC-MSA)