"Non Sum Dignus" (Luke and Plautus)

I am familiar with the Catholic practice of uttering "Domine, non sum dignus" in the so-called "Holy Communion of the Traditional Latin Rite." Moreover, my understanding is that the locus classicus of these words is Luke 7:6 (Vulgata) although I have found a similar use of the operative phrase in Plautus (254-184 BCE). He writes: "Quia enim non sum dignus prae te, ut figam palum in parietem" (from the play, Miles Gloriosus 1140).