Acts 16:25-26

‘But about midnight Paul and Silas were praying and singing hymns to God, and the prisoners were listening to them, and suddenly there was a great earthquake, so that the foundations of the prison-house were shaken, and immediately all the doors were opened, and every one's bands were loosed.'

However, being deprived of their opportunity of worship at the riverside, Paul and Silas, in spite of the pain that they must have been suffering, took the opportunity provided by their situation to pray, that is, to worship, and to sing hymns to God, probably mainly in Greek, but also possibly in Hebrew. And it seems that many prisoners listened interestedly to what they said and sang. This last is Luke's way of indicating that the word was still being effective, even in that prison cell.

That prison had witnessed cursings and imprecations, it had witnessed groanings and cries, it had witnessed pleadings and grovellings. But it had never witnessed anything like this. No prison could hold men who behaved in this way, and suddenly there was a great earthquake which shook the prison house to its foundations. All would recognise that it must be the result of their God Who was responding to His servants. The doors were broken open, and the chains which were fastened to the floors and walls became loosened. The point being stressed here was that God had stepped in and that Paul and Silas had been miraculously made free in response to prayer. The lesson was that no one could hold the servants of God, unless He allowed it. But it was a demonstration rather than a jail break, for they made no attempt to escape. It is in complete contrast with previous description of ‘jail breaks' where those who were freed were led out (Acts 5:19; Acts 12:7).

The doors would only be held by wooden bars so that the movement of the ground causing the doorposts to widen would necessarily release the bars, with the result that the trembling would force the doors open. The cracking of the walls would ensure the release of the chains which were attached to them. In one sense there was no miracle. It was simply a natural catastrophe. It was all in the timing.

Yet the prisoners did not escape. This confirms both the reality of the earthquake, which left conditions such that escape was not so simple as it sounded, and the condition which it left the building in, which clearly made escape difficult, especially in pitch darkness. Furthermore while they may no longer have been fastened to the walls and floors of the prison, the prisoners would still be handicapped by chains and fearful of any guards who would show no mercy to escaping prisoners, and none knew where the guards were or whether there would be another quake. It was safer to remain where they were until morning came. The prison had withstood the shock well and appeared safe enough.