Intertextuality is often treated as a way to solve problems. A phrase that has puzzled readers for a long time becomes clear once it is compared with an older or contemporary text that uses the same language. A gap in a story fills in when a second account gives what the first left out. An argument that looks like a misquotation turns out to follow the version of scripture the writer was actually using. Comparing texts can resolve problems that studying a single passage on its own cannot.

Rather than closing a question, these solutions more often move it somewhere else. The connection that explains a strange line usually raises a new problem about how the two texts are related, which came first, or why they disagree. The answer and the new problem come from the same comparison, since answering the first question is what raises the second. Three well-known cases show how this works, and in each one the gain and the cost come together.

The Watchers Behind Genesis 6

Few passages in the Hebrew Bible are as short, or as hard to interpret, as the four verses that open Genesis 6.

Genesis 6:1-4
1When humankind began to multiply on the face of the earth, and daughters were born to them, 2the sons of God saw that the daughters of humankind were beautiful. Thus they took wives for themselves from any they chose. 3So the Lord said, “My Spirit will not remain in humankind indefinitely, since they are mortal. They will remain for 120 more years.” 4The Nephilim were on the earth in those days (and also after this) when the sons of God would sleep with the daughters of humankind, who gave birth to their children. They were the mighty heroes of old, the famous men.

The account names the sons of God, the daughters of humankind, and the Nephilim without explaining who any of them are, adds a sudden limit on the human lifespan, and then stops just as the flood is about to be announced. A reader is left to guess whether the sons of God are heavenly beings or powerful men, why their unions are mentioned at all, and how the episode connects to the destruction that follows.

The Book of the Watchers, the oldest part of 1 Enoch, gives the missing explanation. It identifies the sons of God as a group of heavenly watchers who come down, take human wives, father a race of giants, and teach people forbidden knowledge, so that the earth fills with violence and God decides to destroy it. What Genesis leaves unsaid, the Book of the Watchers spells out, turning the brief notice about divine sons and giants into a full story about how the world became corrupt enough to face a flood.

The explanation disagrees with the text it explains, since Genesis puts the cause of the flood on human wickedness, reporting that God saw how great the evil of humankind had become, while the Book of the Watchers blames the ruin of the world on the rebellion of the angels and the giants they fathered, treating the same events as evidence for a different account of where evil began.[1] Reading the two together, the reader who only wanted to know what Genesis meant now has to decide which of the two conflicting explanations of evil to accept, and whether the short Genesis account is a summary of an older and fuller tradition or the starting point the later version expanded.[2] The connection that fills the gap in the story creates a disagreement between the sources that the gap had hidden.

The Greek Behind the Argument

The writers of the New Testament read their scriptures mostly in Greek, in the translation known as the Septuagint, and they quoted that Greek version as their Bible. For most of the New Testament this makes no difference, since the Greek follows the Hebrew closely. In a few places the Greek says something the Hebrew does not, and an argument depends on the exact words that only the Greek supplies.

The most familiar instance concerns the sign given to King Ahaz in Isaiah.

Isaiah 7:14
14For this reason the Lord himself will give you a confirming sign. Look, this young woman is pregnant and will give birth to a son. You, young woman, will name him Immanuel.
LXX Isaiah 7:14
14Therefore the Lord himself will give you a sign. Look, the virgin shall be with child and bear a son, and you shall name him Emmanouel.

The Hebrew word rendered "young woman" describes a woman of marriageable age and says nothing about whether she is a virgin, while the Greek translators chose a word that does carry that sense.[3] The Gospel of Matthew quotes the Greek form when it presents the birth of Jesus as the fulfillment of the sign.[4] The link between Gospel and prophet works only through the Greek, because the Hebrew on its own would not produce it. The connection explains how a first-century writer could tie his account of a miraculous birth to an existing prophecy, and it also shows that the tie depends on a translation that differs from its source. Answering how the argument works raises the harder question of what it means to base a claim on a word the Hebrew does not contain.

The Letter to the Hebrews shows the same trade more sharply. Its argument that Jesus came into the world to offer his own body rests on a quotation of Psalm 40, where the speaker tells God that sacrifice and offering were not wanted but that a body had been prepared for him. The standard Hebrew of the psalm says nothing about a body and reads instead that God had dug, or opened, the speaker's ears, an image of obedience rather than of a body offered for sacrifice.[5] The word "body" comes from the Greek, and it may be a reading found only in the Letter to the Hebrews rather than in the common Greek text.[6] The quotation is what makes the argument possible, and it also ties the argument to a complicated history of copying in which the key word may have entered by mistake rather than by translation. The link settles how the author reached his conclusion and gives the reader a new problem about which form of the text is original.

The Council Behind Deuteronomy 32

Deuteronomy 32 recalls a moment when God divided up the nations of the earth and fixed their borders. The standard Hebrew text says he set those borders according to the number of the sons of Israel, a line that has long puzzled readers, since Israel did not yet exist when the nations were divided and there is no clear reason the number of the world's peoples should match the number of Jacob's sons. A manuscript of Deuteronomy found at Qumran and the Greek translation preserve a different reading. Where the standard text has "sons of Israel," they read "sons of God" and "angels of God," describing a scene in which God divides the nations among the members of his heavenly court while keeping Israel as his own share.[7] This reading makes sense of the numbers, since the count of nations now matches the number of heavenly beings rather than a family that had not yet been born.

The reading that solves the puzzle also describes a council of lesser divine beings, each placed over a nation, which fits poorly with the claim a few verses later in the same poem that there is no god besides the God of Israel. The standard Hebrew "sons of Israel" looks like a later change made to ease that tension.[8] Recovering the older reading solves a problem of meaning and creates a problem of theology, and it leaves the further question of why the text was changed and what the change was meant to protect. The manuscript that clears up the numbers reopens the question of how sharply early Israelite writers drew the line between their God and the other powers of the heavens.

The Shape of the Resolution

These three examples share similar questions and intertextual answers, as a connection that answers a small, local question, about a gap in a story, an odd quotation, or a puzzling number, turns it into a larger question about sources, translations, and the history of the text. The difficulty is not removed but traded for a bigger one that goes further into how the texts were written.

Understanding this theoretical trade is what makes the reading worth doing, because the new problems are often more interesting and useful than the ones they replace, and can only be seen when reading one text through another. A puzzle contained in a single passage keeps the reader inside that passage, while a question about the relationship between two texts leads into the tradition that produced both. Comparing texts is worth the trouble because it swaps small, closed questions for larger, open ones, and the fact that the new questions are harder is a sign that the comparison has done real work.