question #3 Sahih Muslim 862b, Book 7, Hadith 46 : What can be inferred about the authenticity of practices based on the testimony of companions who observed the Prophet (ﷺ) directly?

Jabir b. Samura said that the Messenger of Allah (ﷺ) used to deliver the sermon while standing. He would then sit down and then stand up and address in a standing posture; and whoever informed you that he (the Holy Prophet) delivered the sermon while sitting told a lie. By Allah. I prayed with him more than two thousand times.