But Jews came from Antioch and Iconium, and having persuaded the crowds, they stoned Paul and dragged him out of the city, supposing that he was dead. But when the disciples gathered about him, he rose up and entered the city, and on the next day he went on with Barnabas to Derbe. When they had preached the gospel to that city and had made many disciples, they returned to Lystra and to Iconium and to Antioch, strengthening the souls of the disciples, encouraging them to continue in the faith, and saying that through many tribulations we must enter the kingdom of God. And when they had appointed elders for them in every church, with prayer and fasting they committed them to the Lord in whom they had believed. (Acts 14:19-23)
Stoning was the sentence required by the Jewish law for those who spoke against their religion.
What to say then? Why was it safe for Paul to go back into Lystra afterwards? It was safe because the punishment, having been carried out in the correct way according to the law, was now completed.
Barnabas and Paul – although injured – then continued with the work of making disciples.