'Happened' in the Bible

The words of Nehemiah son of Hacaliah. It happened in the month of Kislev, in the twentieth year, that I myself was in the citadel in Susa,

It happened in the month of Nisan, in the twentieth year of King Artaxerxes, when wine was before him, I carried the wine and gave it to the king. And I had never been sad before the king.

Now it happened when Sanballat heard that we were building the wall, [he] became angry and greatly provoked, and he mocked the Jews.

It happened when our enemies heard that their plan was known to us, that God had frustrated [it], and we all returned to the wall--each to his work.

So I sent to him saying, "None of these words you have spoken has happened. You are indeed saying [things] created in your own mind"--

So it happened when they heard the law that they separated all of the foreign people from Israel.