Esther 9:31

to confirm these days of Purim, in their time appointed, according as Mordecai the Jew and Esther the queen had ordained concerning them: like as they upon their soul and upon their seed had confirmed the acts of the fasting and of her complaint.

Esther 4:3

And in all lands and places, as far as the king's word and commandment extended, there was great lamentation among the Jews and many fasted, wept, mourned and lay in sackcloth and in ashes.

Esther 4:16

'Go thou thy way then, and gather together all the Jews that are found at Susa, and fast ye for me, that ye eat not and drink not in three days, neither day nor night. I and my damsels will fast likewise, and so will I go in to the king contrary to the commandment: if I perish, I perish.'"

Jonah 3:2-9

"Up, and get thee to Nineveh that great city, and preach unto them the preaching which I bade 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
And the Jews set it up, and took it upon them and their seed, and upon all such as joined themselves unto them, that they would not miss to observe these two days yearly, according as they were written and appointed;

The fastings

Esther 4:3
And in all lands and places, as far as the king's word and commandment extended, there was great lamentation among the Jews and many fasted, wept, mourned and lay in sackcloth and in ashes.
Jonah 3:2
"Up, and get thee to Nineveh that great city, and preach unto them the preaching which I bade thee."