'Letters' in the Bible

Then Hezekiah sent to all Israel and Judah, and he also wrote letters to Ephraim and Manasseh, to come to the house of Yahweh in Jerusalem to make a Passover feast to Yahweh the God of Israel.

And he wrote letters to treat Yahweh the God of Israel with contempt and spoke against him, saying, "As the gods of the nations of the earth who did not save their people from my hand, so likewise the God of Hezekiah will not save his people from my hand."