Figures of speech are an indispensable component of all languages, and there are some 200 varieties of figures of speech in the Bible. The figure we are going to cover in this article is “idiom.” I assert that, “An idiom is a figure of emphasis, and is the use of a word or words that is peculiar to itself in that it has a meaning that cannot be derived from the literal meaning of the word or words.” You reply, “You’re pulling my leg, right?” I say, “No way, dude! That’s pure octane, the real deal.” You say, “Word up!”
Did you understand the last few sentences? You probably did if you live in the United States of America and watch a lot of television and/or have a teenager. Idioms have to be individually learned because the meaning of the words is not literal, but assigned by the culture. When I spent a summer in Israel, some of us sometimes spoke in idioms because our Israeli hosts could not tell what we were saying—fun for us and frustrating to them (hey, I was still green in my Christian life, wet behind the ears, my bad, I would never do that today). My Jewish friends spoke “school English,” and knew the words we were using, but not the idiomatic meaning. Some idioms are common enough to human experience that they exist in many cultures. Both the Bible and English, for example, speak of the “face” of the earth.
The Bible has many idioms, and if we are going to understand it, we need to understand them. One that we have spent considerable time on is the prophetic perfect. In that idiom, a future action that is certain to occur is spoken of in the past tense. For example, speaking of the return of Jesus Christ, Jude 1:14 literally says, “…the Lord came with myriads of his holy ones.” Why put his coming in the past, when it is future? It is an idiom of the language to emphasize the certainty of Jesus’ coming. 
Another biblical idiom is that God is called the “light,” more than just because of the light that He created, but because of the mental and spiritual light that He brings. Thus He is compared to the sun.
For the LORD God is a sun and shield… 
It makes perfect sense, then, that the Son of God, who revealed the Father and brought light to the world, would be idiomatically called “the sun of righteousness” and the “sunrise from on High.”
But for you who revere my name, the sun of righteousness will rise with healing in its wings. And you will go out and leap like calves released from the stall. 
I can remember reading this verse as a new Christian and knowing that it referred to Jesus Christ, but not knowing why he was called the “sun” and not the “son.” The answer is that in the biblical idiom, Jesus was the sun because he brought the light of his Father to the world. Thus he said, “…I am the light of the world.” By calling Jesus the “sun,” the idiom reveals truth succinctly and powerfully: he brings mental and spiritual light, exposes what is done in darkness, warms the soul, and makes plain the path of righteousness. Zachariah, the father of John the Baptist, referred to Jesus as the rising sun.
because of the tender mercy of our God, by which the rising sun will come to us from heaven.
This verse makes no sense if you do not know the idiom. How can the “rising sun” come from heaven? It comes from below the horizon and rises up into heaven. Knowing the idiom makes the verse both clear and powerful. Thanks be to God our Father, who sent the Messiah, the rising sun, from heaven by creating seed inside Mary. Jesus is indeed the rising sun, bringing light and truth into the world. Have you let him rise in your heart?
 For a much more thorough explanation of this important idiom, see “The Prophetic Perfect,” in our book by John Schoenheit, The Christian’s Hope: The Anchor of the Soul (Christian Educational Services, Indianapolis, IN, 2004), Appendix E, pp. 223-240.
 This is also a use of metaphor, a comparison by representation.
 The “wings” are actually the “borders,” and thus it was foretold that Jesus would have healing in the borders of his garments, something fulfilled in his ministry (Cp. Mark 5:27-29, 6:56).