Esther 9:27

so the Jews took upon themselves and their posterity, and upon all that joined them, never to use those days in any other manner.

And Mardochæus established it, and the Jews took upon themselves, and upon their seed, and upon those that were joined to them to observe it, neither would they on any account behave differently: but these days were to be a memorial kept in every generation, and city, and family, and province.