So the LORD God caused a deep sleep to fall upon the man, and while he slept took one of his ribs and closed up its place with flesh. Genesis 2:21 ESV
Ribs – Except for this passage (side of man) and 2 Samuel 16:13 (side of hill), this word (sela’) is usually about an architectural component. In other words, it describes building materials or building components like chambers or boards or doors. “Ribs” is probably a completely inadequate translation. What the text suggests is that God took the construction material for woman from man.
Why do we need to have this detail? Why didn’t God just make a woman like he made the man? The fact that God used material from the man to make the woman has some enormous relationship implications. First, this action tells us that man and woman are inextricably linked. The full picture of human being includes both and neither is complete without the other. This, of course, does not mean that every individual man or woman must have a partner in order to be God’s representative in the world. Rather it means that the total picture of what being human means is both male and female, and on this level there is no hierarchical difference between the two. Both are formed by God. Both have equal status before Him. Both are linked to each other.
Secondly, this word shows us that the Man must give up something of himself in order for Woman to be. Adam expresses this wonderful mystery when he says, “This is flesh of my flesh, bone of my bone.” Giving up something of himself produces precisely what he was missing. The paradox is plain. In order to be all that I am I must give away part of what I am. The illusion that I am complete within myself is revealed as a false assessment of being in the world. I am complete only when I give away myself.
We have already examined the exclamation of Adam and the fact that he is the first to use the Hebrew word ish, a word that is about the summary of relationships, not individual existence. But now we see that the Man is not just the nexus of all his relationships. He is also the extension of himself in the life of another. He is because he gives.
In the end, marriage is about ribs. Marriage is about giving away my side so that I might let God close the place with flesh. Marriage is about recognizing that I am who this other is. Marriage is about living with myself in the body and soul of my partner. And that’s why it takes a lifetime to be married. I must learn to give away all the ribs until we become one again.
“Male and female were summoned by their creator to act in unison in order to act successfully. Yet they were not charged with the task of existing in unison, in order to cleanse, redeem, and hallow their existence.” That must come from the gift.
Topical Index: sela’, rib, side, marriage, Genesis 2:21
 Joseph Soloveitchik, The Lonely Man of Faith, p. 32.