'Letters' in the Bible

Ahab had seventy sons [and grandsons] in Samaria. So Jehu wrote letters and sent them to Samaria, to the rulers of Jezreel, to the elders, and to the guardians of the children of Ahab, saying,

At that time Berodach-baladan a son of Baladan, king of Babylon, sent letters and a gift to Hezekiah, for he had heard that Hezekiah had been sick.