Ati reported that he saw people praying after the Asr prayer and said, "You are performing a prayer that we never saw the Prophet ﷺ perform during our companionship with him. Indeed, he forbade it," meaning the two units of prayer after Asr.
حدثنا حجاج قال حدثنا شعبة عن أبي التياح قال سمعت حمران بن أبان يحدث
أنه رأى أناسا يصلون بعد العصر فقال إنكم لتصلون صلاة قد صحبنا النبي ﷺ فما رأيناه يصليها ولقد نهى عنها يعني الركعتين بعد العصر
Its chain of transmission is sahih. Imran bin Aban is one of the trustworthy narrators among the Followers, and his hadith is found in all the major collections. Abu Tayah is Yazid bin Humayd, who is trustworthy, and all his narrators have already been mentioned. This hadith has already appeared at 16850.