In certain registers of Persian (Shiite) religious discourse, additional vowel duration conveys several pragmatic meanings. Such additional duration is exerted on the second vowel in the name Muhammad and the first vowel of the title Qa?em - a respectful title of Imam al-Mahdi. The duration serves two purposes: it conveys the preacher's reverence and politeness toward the dignitaries mentioned; it also makes the audience (hearers as well as bystanders) give a variety of appropriate (non-)verbal responses. On the other hand, the phenomenon may be well regarded as a hybrid speech act, too: it has an expressive function on the part of the pr! eacher, and a directive function for the audience.