John Calvin Commentary Acts 23:32

"But on the morrow they left the horsemen to go with him, and returned to the castle:" — Acts 23:32 (ASV)

And the next day. Although Luke did not previously state that the soldiers were commanded to return before they reached their destination, it is certain that they were appointed to accompany him only to that place where the chief captain thought Paul would be safe; for he had departed secretly in the night. And the chief captain knew that as soon as they had finished some part of their journey, there was no further danger, because the adversaries could have no hope of overtaking him; and he knew that it was not wise to send part of the garrison far away.