The Bible is the word of God. Although some of it represents personal letters or open letters, a vast majority of it contains historical narrative. Literally, these are stories of actual events.
When people speak to one another, such as in letter form, they might use a figure of speech like “today was the best day ever”. In personal conversations this statement might be just a general statement; it might be in context of something or might just be a bridge comment to express some sort of connecting thought. But when people are writing out events, any idiom they use will still describe the events they are recording. These idioms also must be readily understood by their readers. In other words, historical narratives describe events even if using idioms. In the Bible, those events involve God as an actor.
This poses an acute problem for the Calvinist. God is described in many narratives of events portraying actions that the Calvinist wishes to deny. Getting a Calvinist just to detail the events described in the Bible is like wresting a greased pig. They don’t want to do it. They inherently know that words, even idioms, have to mean something, and that “something” will undermine their theology.
Forget what the verses means, forget figurative possible interpretations. The Calvinist will refuse to detail the actual events themselves. One prime example is 1 Kings 22:
1Ki 22:19 And he said, Hear thou therefore the word of the LORD: I saw the LORD sitting on his throne, and all the host of heaven standing by him on his right hand and on his left.
1Ki 22:20 And the LORD said, Who shall persuade Ahab, that he may go up and fall at Ramothgilead? And one said on this manner, and another said on that manner.
1Ki 22:21 And there came forth a spirit, and stood before the LORD, and said, I will persuade him.
1Ki 22:22 And the LORD said unto him, Wherewith? And he said, I will go forth, and I will be a lying spirit in the mouth of all his prophets. And he said, Thou shalt persuade him, and prevail also: go forth, and do so.
1Ki 22:23 Now therefore, behold, the LORD hath put a lying spirit in the mouth of all these thy prophets, and the LORD hath spoken evil concerning thee.
Try to get a Calvinist just to give a summary of the events. What do the verses detail happening? They will not do it. Instead they want to talk about word definitions in the text or “anthropomorphisms”. But when pressed just to give a brief summary of what the text says, they will not utter a peep. They inherently know that if they detail out the text in narrative form, then they will undermine their entire view of God. All their eggs are in one basket, so they just claim the text does not mean what it says and try to focus on other parts of the Bible.