The believers asked God to help them speak boldly to people about Jesus.
29 "So now, Lord, listen to what they are saying about punishing us! Help us who serve you (sg) to very boldly speak messages from you (sg) about Jesus 30 Also, by your power [MTY] miraculously heal sick people and do other amazing miracles [SYN] that show people your power! Ask Jesus, who always serves you, to give us the authority [MTY] to do such miracles!"
God shook the place where they were, and his Spirit enabled them to speak his words boldly.
Acts 4:31
31 When the believers had finished praying, the place where they were meeting shook. All of them were ◄completely controlled/empowered► by the Holy Spirit {the Holy Spirit ◄completely controlled/empowered► all of them}, with the result that they began to speak boldly the words that God told them to speak.
Acts 4:32-35