I offered the Friday prayer along with him in enclosure. When I uttered the salutation I stood up in my place and prayed. When he went in, he sent me a message saying: Never again do what you have done. When you pray the Friday prayer, you must not join another prayer to it till you have engaged in conversation or gone out, for the Prophet of Allah ﷺ gave the precise command not to join on prayer till you have engaged in conversation or gone out. (Using translation from Abū Dāʾūd 1129)
عَنْ شَيْءٍ رَآهُ مِنْهُ مُعَاوِيَةُ فِي الصَّلَاةِ قَالَ نَعَمْ صَلَّيْتُ مَعَهُ الْجُمُعَةَ فِي الْمَقْصُورَةِ فَلَمَّا سَلَّمَ قُمْتُ فِي مَقَامِي فَصَلَّيْتُ فَلَمَّا دَخَلَ أَرْسَلَ إِلَيَّ فَقَالَ لَا تَعُدْ لِمَا فَعَلْتَ إِذَا صَلَّيْتَ الْجُمُعَةَ فَلَا تَصِلْهَا بِصَلَاةٍ حَتَّى تَخْرُجَ أَوْ تَكَلَّمَ فَإِنَّ نَبِيَّ اللهِ ﷺ أَمَرَ بِذَلِكَ أَنْ لَا تُوصَلَ صَلَاةٌ بِصَلَاةٍ حَتَّى تَخْرُجَ أَوْ تَكَلَّمَ