This study reports on how the formulas of invoking blessings on Prophet Muhammad in Egyptian Arabic have mostly departed from their semantic/referential religious meanings to express various pragmatic functions. The data is composed of 390 formulas occurring in natural speech, and it was analyzed depending on the speech acts theory by Austin (1962) and Searle (1969, 1976) and the politeness model suggested by Brown and Levinson (1987). The results show that the pragmatic functions expressed through the formulas include six functions: warding off the evil eye, stopping misbehavior, attracting attention, holding the floor, hesitation and mitigating sarcasm. The results also show that the formulas of invoking blessings on Prophet Muhammad positively correlate with age but negatively with education; the older and less educated speakers are, the more formulas are used. Neither the speakers' gender nor residence type (town versus the countryside) triggers significant differences in using more or fewer formulas.