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.