I saw the Prophet ﷺ delivering the sermon standing, then he would sit down briefly without speaking, and he continued the hadith.
حدثنا أبو كامل حدثنا أبو عوانة عن سماك بن حرب
رأيت النبي ﷺ يخطب قائما ثم يقعد قعدة لا يتكلم وساق الحديث
[Its chain of transmission is sahih] Nasai narrated it in the chapter on sitting between the two sermons and being silent during it, in the book of the prayer of the two Eids, no. 1584, from the hadith of Abu Awana, with this wording. Ibn Mulaqqin graded it sahih in Tuhfat al-Muhtaj, 1/497, no. 0608.