Treasury of Scripture Knowledge

Summary

To confirm these days of Purim in their times appointed, according as Mordecai the Jew and Esther the queen had enjoined them, and as they had decreed for themselves and for their seed, the matters of the fastings and their cry.

And for their seed

The fastings

Bible References

And for their seed

Esther 9:27
The Jews made a rule and established a custom that all their descendents should observe two days every year as ordered in the letter, at the fixed time every year.

The fastings

Esther 4:3
Throughout all the provinces, wherever the king's proclamation was made known, there was loud mourning among the Jews. They fasted, wept, wailed, and most of them put on sackcloth and lay in ashes.
Jonah 3:2
Arise and go to the great city, Nineveh. Proclaim to it the proclamation I give you.