en_tn/act/09/04.md

he fell upon the ground

Possible meanings are that 1) "Saul threw himself to the ground" or 2) "The light caused him to fall to the ground" or 3) "Saul fell to the ground the way one who fainted fell." Saul did not fall accidentally.

why are you persecuting me?

This rhetorical question communicates a rebuke to Saul. In some languages a statement would be more natural (AT): "You are persecuting me!" or a command (AT): "Stop persecuting me!" (See: rc://en/ta/man/translate/figs-rquestion)