When they had prayed, the place where they were gathered was shaken, and they were all filled with the Holy Spirit and spoke the word of God boldly.
In context
29And now, Lord, look at their threats, and grant your servants to speak your word with all boldness, 30as you stretch out your hand to heal and to bring about signs and wonders through the name of your holy servant Jesus.” 31When they had prayed, the place where they were gathered was shaken, and they were all filled with the Holy Spirit and spoke the word of God boldly. 32The whole company of believers was one in heart and soul. No one claimed that any of his possessions was his own; everything they had was held in common. 33With great power the apostles gave their testimony to the resurrection of the Lord Jesus, and great grace was upon them all.