This concerns a passage in 1 Corinthians 7:10. This is a statement concerning divorce amongst Christians converts, namely in Corinth.
To the married I give this command (not I, but the Lord): A wife must not separate from her husband. (NIV)Note that the NIV is not necessarily the best translation, but it has some of the easiest prose to follow. Nonetheless, the exact translation of the verse is not of concern. The point is that Paul says that he has a commandment from the Lord concerning the nature of divorce. This is taken as Paul referring to a teaching of Jesus, and so Paul must think Jesus was a person giving such advice. The advice on divorce should have something to do with that found in the Gospels, namely in Mark 10. There Jesus says that a man that divorces and marries another woman commits adultery, and similarly with the woman. A similar sentiment is found in Matthew 5. However, there the simple act of getting a divorce makes the woman an adulteress. Also importantly, this is to be in contrast to Deuteronomy 24:1 which gives the ability to divorce.
So, first note that if Matthew has the original saying of Jesus, it doesn't fit the Pauline version very well. Paul does not say that the mere act of divorcing makes one party an adulterer. In the very next verse
But if she does, she must remain unmarried or else be reconciled to her husband. And a husband must not divorce his wife.Now the divorce can happen, but the woman can remarry only one person. So, perhaps we should assume that the Markan version is the older and Matthew has made the condition stronger. Also, Matthew is dependent on Mark, so this appears to be Matthew taking liberty with the text.
However, Jesus in Mark does not simply say that he is the authority in this matter, and therefore you must listen to him. Rather, Jesus quotes the Old Testament for the proclamation that divorce should not be done. In particular Jesus uses Genesis to say that men and women were designed by God to join together and not be separated. Further, Mark says that no man can separate man and woman. This runs contrary to Paul's version as well; Paul allows there to be separation, but Mark says that no man can make this possible. So Mark and Paul are not in agreement.
Now, does Paul need to be saying that Jesus spoke this commandment in a historical time frame? Paul often uses scripture to back up his position, and he may very well believe that his advice is based on his reading of the Old Testament. For example, Malachi 2 gives a strong pronouncement from God against divorce, in particular saying he hates it. The LXX of Malachi 2:16 says this was spoken by the lord (kurios), the same word used by Paul in 1 Cor 7:10.
So a pronouncement from Jesus in the flesh is not necessary for Paul to claim a commandment from on high about divorce. This does not mean that Paul is not referring to Jesus; I only claim is that it is not a necessary conclusion. On the other hand, what is probable? Considering that Paul's understanding of what Jesus said is significantly different from what is recorded in the Gospels of Mark and Matthew, this gives no reason to think they refer to a recorded source by the Galilean prophet. Further, Mark has Jesus make a scriptural argument, while Matthew uses the force of Jesus' say-so. It looks like the situation is evolving from theological argument amongst the Christians to dictate by Jesus himself. Jesus originally in Mark quotes scripture, and to use the maxim of Bultmann, who remembers the great man quoting somebody else? Worse yet, Luke and John drop this teaching of Jesus; if it went back to the founder, why did Luke think it wasn't worth repeating? He was using Mark, so apparently Luke doesn't have the same problem with divorce; can this really be the case if this is what the very Son of God actually said in history? If instead the commandment was a determination from the Old Testament and revelation, perhaps then Luke's community didn't buy the scriptural argument; that makes a lot more sense than Luke denying the authority of God on earth! If Mark and Paul are only making arguments based on their understanding of the Old Testament or their personal, subjective impressions of the religion, then Luke coming to a different conclusion makes plenty of sense. This becomes significant evidence in favor of no oral tradition starting with the master.
Let us also consider how this commandment of Jesus could have been passed around. Suppose that Paul is in fact quoting his dead master. This means that the authority of Jesus' statements are sufficient to make a matter settled. This is similar for Matthew's Jesus, at least in this one case. However, Mark's Jesus requires a scriptural argument. How did Jesus get demoted from authoritative despot to exeget only to be bumped up again? The historical situation in Mark 10 is unlikely since Pharisees were not running around beyond the Jordan. This is desert land, not a place that needed priestly figures. The context is very strange. It is hard to say that this can go back to this historical situation. Matthew also places this pronouncement in the Galilee, it seems, so the details of substance and location are amiss. Very strange if this is a recollection.
Now, I have utilized the arguments of Early Doherty concerning this particular passage. This argument (#8) is that Paul can very well be claiming that his source is revelation by God/Jesus rather than an oral tradition. This can also make sense of this passage as well as 1 Cor 9:14 which also says that the Lord commands those that preach the gospel must make a living by the gospel. We should also take to heart what Paul says in Galatians 1:11-12 that says he received his gospel by revelation from Jesus himself; he specifically says that no man taught him these things. This works against the notion that Paul learned about what Jesus said from other apostles, and instead he suggests that his information comes from revelation and scripture.
So, the phrase in Paul alone does not need to indicate that Paul is quoting a historical Jesus, and moreover Paul suggests he gained his knowledge about Jesus through revelation and scripture. Without this latter consideration, the historicist stance explains the statement by Paul about as well as the mythicist, but the extra bit from Gal 1 suggests that the mythicist reading of 1 Cor 7 is not strained while the historicist position requires Paul to exaggerate his claims in Galatians. McGrath often argues that the mythicists propose situations that are less probable and require more special pleading in readings of verses. In this case, it seems that this is in fact true for the historicist camp.
Note, this does not mean Jesus wasn't a historical figure just from this argument; it doesn't even establish probability in favor. What it does do is demonstrate that one can justifiably read passages in Paul that some with to use to prove Paul knew a historical Jesus figure can be validly read without ad hoc assertions that fit in the mythicist paradigm. In some ways, it actually fits better in the mythicist paradigm because of the statements in Gal 1. Nonetheless, passages such as 1 Cor 7:10 cannot be used without further justification against the mythicist case.