The Nazarene Jews weren't surprised to see him locate and read from a passage in Isaiah, but when he came back a year later, teaching, they were astounded. This guy's a carpenter. Where'd he get this wisdom? In one of his trips to Jerusalem, according to John, the local Jews asked a similar question. How does this man know so much without having been taught? So Jesus answered. My teaching is not mine but His who sent me.
There's a lot to consider about that response. Let's take God Himself, first of all. Does divine revelation fully explain Jesus' lack of formal education? Conceivably, it could - and it may, at least partly - but that still wouldn't be the whole story. The scriptures do not tell us precisely when Jesus began hearing the voice of his Father internally, but we do know that same Father sent his Son to grow up in a Jewish Synagogue community. Therefore, we should probably look for some balance on this question, to say the least.
Next, even though we may accept, as historical, John's testimony about spiritual phenomena [which is very consistent with his method of inserting factual details into dialogue] we have an additional problem. What does Jesus' response here actually mean? My teaching is not mine but His who sent me. In addition to divine revelation (which I certainly do affirm is the strong implication when considering the rest of John's testimony) the statement could also mean Jesus is simply giving God credit for everything he'd learned in his life, including every scripture he'd heard being read in the Synagogue, since his childhood.
The shema, for instance, was no doubt repeated at least once a week in every prayer house and Hebrew gathering from Egypt to Galilee. It was probably the first and most frequent scripture Jesus ever heard from a very young age, and it famously became "the Greatest Commandment" of His adult ministry. Those are facts. On top of them, it would be thoroughly consistent with everything we know about Jesus for him to credit the shema as God's teaching, instead of his own. Therefore, Jesus' response in Jerusalem plays on two levels. My teaching is not mine but His who sent me. Well of course it was. His teaching summed up the entire Law and the Prophets.
In his whole life in Egypt and Nazareth, Jesus was listening to (weekly, at least), reading (less often) and handling (perhaps much less often) the scriptures. Somehow, Jesus was gaining a much greater depth of understanding through that experience than any other Nazarene Jew at the time, including the leaders. And for this learning experience, among others, Jesus gave all the credit and glory to God.
Thus, Jesus was learning from God in the Nazareth Synagogue even before he was learning from God by divine revelation. Thus, we are finally starting to put together some concrete details about his experience in the Synagogue during the so-called "hidden years". But there is still much more to consider.
To be continued...
Series Update: The Nazareth Synagogue