And they said unto him, Thus saith Hezekiah, This day is a day of trouble and of rebuke and of blasphemy, for the sons are come to the breaking of the water, and there is no strength in her who is to bring them forth.

Then the men feared the LORD exceedingly and offered a sacrifice unto the LORD and made vows.

And fear not those who kill the body but are not able to kill the soul, but rather fear him who is able to destroy both soul and body in hell.

Seek the lord

And from after them out of all the tribes of Israel such as set their hearts to seek the LORD God of Israel came to Jerusalem to sacrifice unto the LORD God of their fathers.

Nevertheless, good things have been found in thee, in that thou hast burned down the groves of the land and hast prepared thy heart to seek God.

Proclaimed

Then all the sons of Israel and all the people went up and came unto the house of God and wept and sat there before the LORD and fasted that day until evening and offered burnt offerings and peace offerings before the LORD.

And they gathered together in Mizpeh and drew water and poured it out before the LORD and fasted on that day and said there, We have sinned against the LORD. And Samuel judged the sons of Israel in Mizpeh.

Then I proclaimed a fast there at the river of Ahava that we might afflict ourselves before our God, to seek of him a right way for us and for our little ones and for all our substance.

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

And it came to pass in the fifth year of Jehoiakim the son of Josiah king of Judah, in the ninth month, that they proclaimed a fast before the LORD to all the people of Jerusalem and to all the people that came from the cities of Judah unto Jerusalem.

And I turned my face unto the Lord God, seeking him in prayer and supplication, in fasting and sackcloth, and ashes:

Sanctify a fast, call a solemn assembly, gather the elders and all the inhabitants of the earth into the house of the LORD your God and cry unto the LORD.

Therefore also now, saith the LORD, turn unto me with all your heart and with fasting and with weeping, and with mourning:

So the people of Nineveh believed God and proclaimed a fast and put on sackcloth, from the greatest of them even to the least of them.

General references

When I am afraid, I will trust in thee.