Jabir b. Samura said, “The Prophet used to preach standing, then he would sit down, then stand and preach standing. If anyone tells you he preached sitting he is lying. I swear by God that I prayed along with him on more than two thousand occasions.” Muslim transmitted it.
Hadith Referenceمشكوة المصابيح / كتاب الصلاة / 1415
Hadith Gradingالألبانی:صَحِيح | زبیر علی زئی:صحيح
Hadith Takhrij´تحقيق و تخريج: محدث العصر حافظ زبير على زئي رحمه الله` «رواه مسلم (862/35)»