This verse, so beloved at weddings, describes the first marriage. It was between two people united in perfect bliss. They were so totally in love with each other, just as man was meant to be with woman. However, at this moment, before the Fall, they could also communicate and understand each other perfectly. There was no sin in the world as of this time, nothing that would cause a breakdown in things.
A majority of commentators favor Moses, under Divinde inspiration, as having penned these words, as the Hebrews’ teacher in the Wilderness. Still others believe this was a continuation of Adam’s thoughts in Verse 23. This is what I, personally, have often felt. It makes sense that God talked with our first ancestor about this helpmate. He would therefore be able to speak prophetically about the institution of marriage. A third possibility is that God Himself spoke these words prophetically, establishing marriage as a sacred institution. God was, in a sense, giving his daughter away to Adam, and this could be a pronouncement by God He had joined the two as one flesh, and that it would be like this in every marriage after that. And, therefore, what God has joined, man should not tear asunder. (Mark 10:9)
Of course, that image – God, as Eve’s Father, giving her away in marriage – is a beautiful image that holds true no matter who the speaker is in this verse. Because, it shows tat the institution of marriage is a holy one. It is one where the parties should act with utmost love and devotion toward each other.
It’s worth noting that the Bible doesn’t mention a man taking a wife. Instead, it mentions him leaving his parents and cleaving to her. This, like the fact that Eve came from Ada’s side, shows a truth about marriage. The man should still love his parents, of course. However, his devotion to his wife should be beyond that. His love for her should be very deep. It should never be just about the physical. Thinking about only the physical robs marriage of its beauty.
See, the two shall be one flesh. Sure, they can have different interests, but they should be willing to give for each other. They must be willing to work together, and agree to work together to build a great life together. This is especially important since the Fall.
Before the Fall, however, it was perfect. The two could much more easily become one flesh. A married couple should grow closer as the years go on. If they aren’t, something is very wrong, and they need help to start getting closer again, because they have chosen to spend a lifetime together. That is what marriage is, a lifetime of loving each other. However, Adam and Eve didn't' have to grow closer.
Picture a married couple who have been together 75 years, complete each other’s sentences, and always know what the other is thinking. They delight in each other all the time. That couple has worked to get to that level. But, without the breakdown in mankind, Adam and Eve were already there.
It’s a great shame that mankind has regressed, since the Fall, to the point it has. As we’ll see, a man named Lamech, in Cain’s line, not only violated the notion that the two would be as one by having a second wife, he totally refused to cleave to his wives. His loud boastings are those of an emotional abuser, one who would take whatever he wants, instead of giving out of love and a lack of selfishness.
For now, however, Adam and Eve had the perfect relationship. There was no problem with communication, no drifting apart, just a couple that truly understood the notion of unconditional love, because they hadn’t yet experienced that sin nature that they would soon bring into the world.