The Messenger of Allah ﷺ used to deliver the two sermons standing, separating them by sitting down between them.
أخبرنا إسمعيل بن مسعود قال حدثنا بشر بن المفضل قال حدثنا عبيد الله عن نافع
أن رسول الله ﷺ كان يخطب الخطبتين وهو قائم وكان يفصل بينهما بجلوس
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Bukhari narrated it in Kitab Al-Jumuah, Bab Al-Qaadah bayn al-khutbatayn yawm al-Jumuah, hadith 928, up to "etc.," hadith 861, from the hadith of Bishr bin Mufaddal. Muslim also narrated it in Kitab Al-Jumuah, Bab Dhikr al-khutbatayn qabl al-salah, from the hadith of Ubaydullah bin Umar with the same wording. It is also found in Al-Kubra, hadith 1722...