SERMON. The oration delivered at the, Friday midday prayer is called the khutbah خطبة; exhortations at any other time are termed wa’zوعظ. The former is at established custom in Islam, and the discourse is always delivered at the Masjidu ‘I-Jami’, or principal mosque, on Fridays, but sermons on other occasions although they are in accordance with the practice of Muhammad, are not common. Very few Maulawis preach except on Fridays. [KHUTBAH.]

Based on Hughes, Dictionary of Islam