Where in Scripture does it say that EVERYTHING God says is a parable? Nowhere! Rather, most of Scripture is plain text. Yes, there are parables. Most of Psalm 78 is parable. Much of what Jesus says in public is parables, but what He says to His disciples in private is not parables. Most of the New Testament and almost all of the Old Testament are not parables.
Think about it in logical terms: if everything God says is a parable, then even the statement, "God is speaking in parables" is itself a parable. That's silly.
Look at the serpent in this verse.
And who will tell that God the Father is speaking in parables when he said WHEN YOU EAT FROM IT YOU WILL SURELY DIE.
Because what God the father said is very clear in serpent understanding.
GENESIS 2:17
17 but you must not eat from the tree of the knowledge of good and evil, for when you eat from it you will certainly die.”
The serpent never believe that God the Father is speaking in parables.
So he said this to Eve.
GENESIS 3:4
4 “You will not certainly die,” the serpent said to the woman. 5 “For God knows that when you eat from it your eyes will be opened, and you will be like God, knowing good and evil.”