The reader might well ask why one would give space to the Friday sermon—the khutbah—in a book on syariah. The answer is that the khutbah is the main vehicle through which the ‘ordinary’ Muslim is instructed in his or her duty to God; it is how that person knows the syariah. The syariah encapsulates theology in the form of prescription. That is what we mean when we say that Islam does not recognize distinctions between law, ethics, morality, the syariah and the totality of these. Any comparison with the contemporary Christian sermon is not sustainable because ‘God's laws’, expressed theologically, are no longer primary in Western society. The law, one's personal and social duty, is found elsewhere, in codes and statutes.

The instructional functions of khutbah are crucial to individual and social duty and they are, thus, syariah texts. In this sense they are the most public of the faces of syariah in all Muslim countries. Indonesia is no exception in this regard, and has its own vibrant khutbahpublishing industry.

The function of the khutbah is purely didactic: to instruct the faithful in religion. This means instructing the Muslim in his or her individual duty to God as this is understood in a particular place, at a certain time. Khutbah are, therefore, specific and local. This may seem obvious, but it was in fact the subject of intense debate in Indonesia in the 1920s through 1950s. The central issue concerned language: should the khutbah be delivered in Indonesian or Arabic? In the 1920s, Nahdlatul Ulama (NU) recommended Arabic accompanied by an Indonesian summary, on the basis that the khutbah is integral to the prescribed ritual prayers (shalat), for which Arabic is required. Although the use of Indonesian has been standard since the 1930s, the same issue occasionally surfaces even now. As Ahmad Hassan, the founder of Persis, said as far back as the 1930s.