Abu Hurairah reported that the Prophet ﷺ said, "Any sermon that does not contain the testimony of faith is like a severed hand."
عن النبي ﷺ قال: كل خطبة ليس فيها تشهد فهى كاليد الجذماء.
Reported by Abu Dawud (4841) and Tirmidhi (1106), both through the route of Asim bin Kulayb, from his father, from Abu Hurairah, who narrated it. Its chain of transmission is hasan, on account of Asim bin Kulayb and his father, for both of them are truthful narrators.