A.T. Robertson Commentary Acts 16:28

"But Paul cried with a loud voice, saying, Do thyself no harm: for we are all here." — Acts 16:28 (ASV)

Do thyself no harm (μηδεν πραξηις σεαυτω κακον). The usual construction (μη and the aorist subjunctive) for a prohibition not to

begin to do a thing. The older Greek would probably have used ποιησηις here. The later Greek does not always preserve the old distinction between ποιεω, to do a thing, and πρασσω, to practice, though πρασσετε keeps it in Php 4:9 and ποιεω is rightly used in Lu 3:10-14. As a matter of fact πρασσω does not occur in Matthew or in Mark, only twice in John, six times in Luke's Gospel, thirteen in Acts, and elsewhere by Paul.

Sprang in (εισεπηδησεν). First aorist active of εισπηδαω, old verb, but here only in the N.T. Cf. εκπηδαω in 14:14. The jailor was at the outer door and he wanted lights to see what was inside in the inner prison.