# they had ... upon them, they threw them ... keep them
the magistrates had ... upon Paul and Silas, the magistrates threw Paul and Silas ... keep Paul and Silas
# had laid many blows upon them
"had hit them many times with rods"
# commanded the jailer to keep them securely
"told the jailer to make sure they did not get out"
# jailer
a person responsible for all the people held in the jail or prison