And when they had taken security of Jason - This is an expression taken from courts, and means that Jason and the other gave satisfaction to the magistrates for the good conduct of Paul and Silas, or became responsible for it. Whether it was by depositing a sum of money, and by thus giving bail, is not quite clear. The sense is, that they did it in accordance with the Roman usages, and gave sufficient security for the good conduct of Paul and Silas. Heuman supposes that the pledge given was that they should leave the city. Michaelis thinks that they gave a pledge that they would no more harbor them; but if they returned again to them, they would deliver them to the magistrates.
And of the other - The other brethren Acts 17:6 who had been drawn to the rulers of the city.

Taken security - Λαβοντες το ἱκανον, Having taken what was sufficient, or satisfactory. Sufficient for the present, to prove that the apostles were upright, peaceable, and loyal men; and that Jason and his friends were the like, and would be, at any time, forthcoming to answer for their conduct. Perhaps this is the sense of the phrase in the text.

And when they had taken (c) security of Jason, and of the other, they let them go.
(c) When Jason had put them in good assurance that they would appear.

And when they had taken security of Jason, and of the other,.... That is, received satisfaction from them, by the defence which they made for themselves, and the apostles, by the account that they gave of them and of their doctrines; whereby it plainly appeared to the full satisfaction of the magistrates, that their principles had no tendency to move sedition, or to alter the form of their government, or to do anything detrimental to Caesar, as was suggested: the Syriac, and Arabic versions render it, "took sureties"; of them for their good behaviour, and that they would be forthcoming, whenever called for:
they let them go; about their business, to their own houses, and company, and did not inflict any punishment upon them, or commit them to prison.

And when they had taken security of Jason and of the other--"the others"--probably making them deposit a money pledge that the preachers should not again endanger the public peace.