The Messenger of Allah (ﷺ) used to deliver two khutbahs standing, and he would separate them by sitting.
Sunan an-Nasa'i Book 14, Hadith 53
← Previous Hadith "I sat with the Prophet (ﷺ) and I did not see him deliver the khutbah except standing, and he sat, then he stood up and delivered the second khutbah."

Sunan an-Nasa'i Book 14, Hadith 52 Next Hadith → "I saw the Messenger of Allah (ﷺ) delivering the khutbah on Friday standing, then he sat briefly and did not speak, then he stood up and delivered a second khutbah. So whoever tells you that the Messenger of Allah (ﷺ) used to deliver the khutbah seated, he has lied."

Sunan an-Nasa'i Book 14, Hadith 54