Classical Arabic is the oldest type of Arabic that is studied widely. It is the language of the Qur’an and texts from the classical age of the Islamic empire (including texts dealing with Qur’anic subjects), the Hadith (the record of the Prophet Muhammad's (peace be upon him) words and actions), Islamic law (fiqh) and theology ('aqida), history, biography (sirah), geography, poetry, grammar (nahu), medicine, astronomy, and other sciences. Until a few decades ago, this was the type of Arabic most commonly taught in American universities. Classical Arabic is still used today, but is restricted to religious and highly formal contexts.