The passage also defines what “keeping” the days looks like: feasting and joy, sharing food portions with one another, and giving gifts to the poor. Purim is not presented as private feeling but as a public, communal practice with social generosity built in.

Where interpretation differs

How “binding” the Purim ordinance is

Some readers take the language (“ordained,” “took on them,” “so that it should not fail”) to mean the community is establishing a lasting obligation that carries real moral weight for later generations (inference from the intensity and permanence language). Others read it as the narrative description of a strong custom—authoritative within the story world and widely accepted—but not necessarily equal to laws given earlier in Scripture (inference from Purim’s origin in historical events and letters rather than at Sinai).

Who is included in “all such as joined themselves to them”

Some understand this phrase to include non-Jews who formally attached themselves to the Jewish community (for example, through loyalty and shared identity). Others understand it more narrowly as Jews who aligned themselves with the communal decision, emphasizing internal solidarity rather than conversion.

Why the disagreement exists

The text uses both communal-language (“the Jews ordained”) and strong permanence-language (“should not fail… throughout every generation”), while rooting the practice in imperial letters and lived experience (“what they had seen… what had come to them”). Readers weigh those features differently when deciding whether Purim here functions like an enduring religious requirement or like a community-established memorial practice.

What this passage clearly contributes

• It shows how diaspora communities preserved identity through shared calendar practices coordinated by letters across provinces.
• It anchors Purim’s meaning in reversal: the “month” turned from grief to joy and from mourning to a “good day” (explicit claim).
• It defines celebration as including care for the vulnerable (“gifts to the poor”), not only feasting (explicit claim).
• It connects the name “Purim” to “Pur” (lot), highlighting the irony that what was used to plan destruction became attached to a yearly remembrance of survival (explicit claim).
• It emphasizes intergenerational memory: every family, province, and city is included in the stated goal that the remembrance not disappear.

Esther 9:20–28