12After this he went down to Capernaum with his mother, his brothers, and his disciples; and they remained there a few days. 13The Passover of the Jews was near, and Jesus went up to Jerusalem. 14In the temple he found people selling cattle, sheep, and doves, and the money changers seated at their tables. 15Making a whip of cords, he drove all of them out of the temple, both the sheep and the cattle. He also poured out the coins of the money changers and overturned their tables. 16He told those who were selling the doves, “Take these things out of here! Stop making my Father’s house a marketplace!” 17His disciples remembered that it was written, “Zeal for your house will consume me.” 18The Jews then said to him, “What sign can you show us for doing this?” 19Jesus answered them, “Destroy this temple, and in three days I will raise it up.” 20The Jews then said, “This temple has been under construction for forty-six years, and will you raise it up in three days?” 21But he was speaking of the temple of his body. 22After he was raised from the dead, his disciples remembered that he had said this; and they believed the scripture and the word that Jesus had spoken.In this vignette, after the miracle at the wedding, Jesus goes up to Jerusalem for Passover. Once in the temple, Jesus takes drastic action. He fashions a whip out of cords and begins using it on the merchants and animals there. The table of the money changers gets overturned. Then he makes it over to the area where birds were being sold. There wasn't much he could do there except tell the owners to take their cages and get out. However, his statement at this point is rather interesting. We get introduced to one of the great Johannine themes, Jesus' familial relationship with God. Jesus was claiming his intimate relationship with God as grounds for his actions. Additionally, by referring to Zechariah 14, Jesus was claiming to inaugurate the Messianic age of the rule of God. In both cases, Jesus was claiming divine mandate.
23When he was in Jerusalem during the Passover festival, many believed in his name because they saw the signs that he was doing.24But Jesus on his part would not entrust himself to them, because he knew all people 25and needed no one to testify about anyone; for he himself knew what was in everyone. (NRSV)
Contrary to its chronological placement in John, Jesus' actions in the temple led to his death. The disciples, naturally linked this connection back with Scripture. They understood much more clearly, in retrospect.
Jesus was challenged here by the priests. What was his authority? Did he have more than just his own word to support his Messianic claim? They wanted a sign of his Messianic status and his approval of his father. Jesus would only offer a laughable sign, that he would rebuild the temple three days after the Jews destroyed it (why would they destroy the temple? - perhaps it's a sly statement of their own culpability in the destruction of 70 CE?). Of course they scoff at it. But in John, that leads us to another "of course," of course they misunderstood him, even though he seemed to be making a straightforward (though ridiculous) claim. Jesus was actually speaking about his body, about his resurrection. "Jesus refused to give a sign in proof of his authority, such as would enable men to identify him without risks, without committing themselves to him."
Here we have a story that contrasts with the preceding. When Jesus turned the water into wine, the disciples saw his glory and believed. They were received by Jesus. However, Jesus is much more wary of the faith he is producing in the crowds this time around. Something about their faith was inadequate. It sprung from poor character, presumably from people who were likely to fall away in the end. So Jesus lacked faith in them and kept his distance. However, those who were received by Jesus had their faith rewarded and validated by the resurrection. They were given new eyes to understand what had happened that day, and new ears to hear Jesus' promise of restoration of the temple.
In this redefinition of Jesus' words about rebuilding the temple, are we to hear any disappointment that he did not show up to rebuild it after its destruction in 70?
 Contrary to many commentators, I see no critique on the part of the temple establishment here in John's gospel. As Keener points out, there's no reason to believe the priests profited from the sales in the temple. Assuredly the Essenes would have alerted us to that fact. Also, as von Wahlde suggests, there is non reason to see Jesus as a replacement of the temple.
 As Keener notes, readers of ancient biography would not have expected chronological presentation.
 Contrary to most commentators, I see no need for the priests to have been unaware of Jesus statement in verse 16. Verse 18 seems to presuppose that they did hear him.
 Bultmann, p. 125.