en_tn/est/09/31.md

These letters

You may need to use a word for written instructions that is more general than "letter" so that the reader does not think that these documents were about only personal matters.

The Jews accepted this obligation for themselves and their descendants

Accepting an obligation is a metaphor for agreeing with the obligation. The abstract noun "obligation" can be expressed with the verb "obligate." Alternate translation: "The Jews agreed and said that they and their descendants were obligated to celebrate the days of Purim" (See: rc://en/ta/man/jit/figs-metaphor and rc://en/ta/man/jit/figs-abstractnouns)

they accepted times of fasting and lamenting

Accepting times of fasting and lamenting is a metaphor for agreeing to fast and lament at certain times. Alternate translation: "they agreed to fast and lament at certain times" (See: rc://en/ta/man/jit/figs-metaphor)