'Keep' in the Bible

Then Haman said to King Ahasuerus, “There is a certain people scattered [abroad] and dispersed among the peoples in all the provinces of your kingdom; their laws are different from those of all other people, and they do not observe the king’s laws. Therefore it is not in the king’s interest to [tolerate them and] let them stay here.

For if you remain silent at this time, liberation and rescue will arise for the Jews from another place, and you and your father’s house will perish [since you did not help when you had the chance]. And who knows whether you have attained royalty for such a time as this [and for this very purpose]?”

obliging them to celebrate the fourteenth day of the month of Adar, and the fifteenth day of the same month, annually,

the Jews established and made it a custom for themselves and for their descendants and for all who joined them, so that they would not fail to celebrate these two days as it was written and at the appointed time annually.