It is narrated from Sayyiduna Anas (may Allah be pleased with him), he says that a man delivered a sermon before Sayyiduna Umar (may Allah be pleased with him) and spoke at great length, so Sayyiduna Umar (may Allah be pleased with him) said: Speaking too much in sermons is among the useless acts of Satan.
Hadith Referenceالادب المفرد / كتاب الكلام / 876
Hadith Gradingالألبانی:صحيح
Hadith Takhrij«صحيح : أخرجه ابن وهب فى الجامع : 322 و ابن أبى الدنيا فى الصمت : 152»