Nafi bin Jubayr sent him to Saaib bin Yazid, the nephew of Namir, to ask him about something Muawiya had observed him doing during the prayer.Saaib replied, "Yes. I prayed the Friday prayer with him in the enclosure, and when he gave the closing salaam, I stood up in my place and prayed. When he went inside, he sent for me and said, 'Do not repeat what you did. When you have prayed the Friday prayer, do not join another prayer to it until you have spoken or left the place, for the Prophet of Allah ﷺ commanded this, that one prayer should not be joined directly to another until you leave or speak.'"
حدثنا عبد الرزاق وابن بكر قالا أنا ابن جريج قال
أن نافع بن جبير أرسله إلى السائب بن يزيد ابن أخت نمر يسأله عن شيء رآه منه معاوية في الصلاة فقال نعم صليت معه الجمعة في المقصورة فلما سلم قمت في مقامي فصليت فلما دخل أرسل إلي فقال لا تعد لما فعلت إذا صليت الجمعة فلا تصلها بصلاة حتى تتكلم أو تخرج فإن نبي الله ﷺ أمر بذلك لا توصل بصلاة حتى تخرج أو تتكلم
Its isnad is sahih. Umar bin Ataa bin Abul-Khuwar Makki, the freedman of Banu Amir, is trustworthy, and likewise Nafi bin Jubayr bin Mutim, who is trustworthy and excellent. Saaib bin Yazid Kindi, the son of Namr's sister, is a well-known companion. The hadith was narrated by Muslim, 2/601, no. 883, in the chapter on Friday prayer, on prayer after Friday prayer, and by Abu Dawud, 1/294, no. 1129, similarly, and by Bayhaqi, 2/191.