Esther 9:31

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

Esther 4:3

And in every province, wherever the king's commandment and his decree came, there was great mourning among the Jews, and fasting, and weeping, and wailing: many lay in sackcloth and ashes.

Esther 4:16

Go, gather together all the Jews that are found in Shushan, and fast for me, and neither eat nor drink three days, night or day: I also and my maidens will fast likewise, and so will I go in unto the king, which is not according to the law; and if I perish, I perish.

Jonah 3:2-9

Arise, go to Nineveh, the great city, and preach unto it the preaching that I shall bid thee.

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 ordained and took upon them, and upon their seed, and upon all such as joined themselves to them, so that it should not fail, that they would observe these two days according to their writing and according to their fixed time, every year;

The fastings

Esther 4:3
And in every province, wherever the king's commandment and his decree came, there was great mourning among the Jews, and fasting, and weeping, and wailing: many lay in sackcloth and ashes.
Jonah 3:2
Arise, go to Nineveh, the great city, and preach unto it the preaching that I shall bid thee.