I realize I'm not the first person to have discovered that there is some connection between Isaac and Jesus. However, I always heard it said that Isaac was a type of Christ. I tend to be very weary about this term type. Isaac was Isaac. His story first and foremost tells us about Isaac, though it story is rather short and uneventful in comparison with both the story of his father and that of his sons. Why have people insisted on making a connection between Jesus and Isaac?
Well, there are some Greek and Hebrew words that started it all. In John, Jesus is called the monogenes of God, which we translate variously as the “Only Son,” or the “Only Begotten,” or sometimes “One and Only”. So what? Isaac wasn't Abraham's only son, was he? Well, not exactly, but in Genesis 22 (the story of the sacrifice of Isaac), God calls Isaac Abraham's yechid, Which means, more or less, 'only son'. When Josephus retold the story the sacrifice of Isaac in Greek (Ant. 1:13), he used that Greek word, monogenes, and in fact, so did the author of Hebrews (11:17; The LXX translates the word as agapaton, 'beloved'; a loose translation, but it will also become important).
Why would God call Isaac Abraham's only son? What's Ishmael, chopped liver? Well no, God also blesses Ishmael, and he turns out to be quite a good chap in the end, and has lots of kids, with whom I am becoming acquainted here in Jerusalem (and yes, they are at strife with their brothers). However, Isaac is the only son in a legal sense. He gets all of the inheritance, and he gets all of the blessings. Interesting.
Now, it may be recalled that while the circumstances surrounding Jesus birth were quite extrordinary, he was not really Gods only son. Paul implies, and Luke outright says that Adam was also God's son. By proxy this means (as Luke records Paul saying in Athens) that the whole human race are God's children. In the Old Testament, Israel is also called God's Son, and Jews still refer to themselves as such. But John calls Jesus the only son. This does two things: first, it establishes him as the son of the inheritance (not Abraham's inheritance, necessarily, but actually God's inheritance). The second thing is that it ties Jesus very closely to another story of a father who went out to sacrifice his son. Josephus reports that Isaac was twenty five when he was Sacrificed, and the Talmud says 37. Not a small child. They also report that when he discovered his father's intentions, he willingly went along because it was the will both of his father and of God. John draws on this tradition to explain, in a very Jewish way, the nature and significance of Jesus' son-ship.
I'd like to point out a couple other parallels that I think John may have intended, but perhaps are not quite as blatant in the text. For one, Isaac's story is oddly similar to Abraham's. He marries one of his relatives, he lies to Abimelek about his wife, he builds alters and sacrifices to God, he digs wells, he prospers greatly, etc... Isaac does what his father did. John repeatedly emphasizes that Jesus does the same things as the Father, and that Jesus is essentially carrying on his work. Another thing about Isaac is that, while Abraham was the father of Israel, it is through Isaac. Isaac was the immediate father of Jacob, Israel. John is very clear that those who believe in the Son also become son's of God. That is, God is starting his own nation that will be reckoned through his only Son.
Furthermore, Genesis also mentions that Abraham had dug wells, the Philistines had stopped them up, and Isaac re-opened them. I won't go into that too much, as it's very speculative, but I will allow you to draw your own conclusions based on the significance of water and wells and the presentation of the Jewish leadership in the Gospel of John. But where did John get these ideas? Well I think it has roots in the life of Jesus himself.
When Jesus was baptized there was a voice that said, “You are my Son, my beloved. I am delighted with you.” We often see the connection with Psalm 2:7, where it says “The LORD said to me, 'You are my Son. Today, I have begotten you.'” We take this to be a reference both to his divine paternity and his Kingship (as it is originally in Psalm 2). I think there is a connection, but that isn't the only connection one can find, It's just the most obvious in English. If you were a good Hellenistic Jew or Christian in the first century, you would know that in your LXX translation Genesis 22, God repeatedly calls Isaac “Your son, your beloved,” as a translation of yechid, 'only'.
Now, I wasn't there when God spoke, but if I were a betting man, I'd say (assuming God was speaking Hebrew, which is reasonable for that place and time) he called Jesus his yechid. We still have the echo of Psalm 2, but we have a much stronger echo of Genesis 22. I believe the Gospel writers recognized this very well, and chose a translation that would alert their readers to look into the correct scripture. Too bad our translators haven't done us the service. (Not that they can really be blamed for giving us literal translations of the Greek and Hebrew, respectively). Another connection is in a little recounted story of Isaac where it says that there was a famine, but God told him not to go to Egypt, so he moved to Gerar with Abimelek and blah, blah, blah... and (Gen. 26:12) 'Isaac sowed seed in the land, and in the same year he reaped one hundred fold.' Wait... what? He sowed seed and reaped one hundred fold? Kinda reminds me of another story about a sower who sowed his seed and reaped one hundred fold...
Better to same that one for another time...
PS: I realize I totally crapped out on that lectionary thing. I did begin research for posts about it, but it was a lot lot lot of work, an usually by the time I could get sorted about the readings and their relationship, the week had long past. If I was a preacher, and it was my job to preach from the readings every week, I would definitely do it, but I don't really have the time.
By the way, I think I'm going to post my conclusions about Hebrew Matthew tomorrow.