Destroy this temple: Herod the Great started rebuilding the temple's grand structure in 20 BC. The work continued until AD 64. This is why Jesus amazed his audience when he claimed he could destroy and rebuild it in a few days.
However, Jesus was speaking figuratively (using a word picture) about his own body. He described his body as the true temple, the place where God was present (see 1:14, 51).
His body would be destroyed. Three days later, God would raise him from the dead. Through his resurrection, Jesus showed that he himself was now the true place where people meet God. Because of this, the Jerusalem Temple and its sacrifices were no longer necessary.
Later, during the trial of Jesus, some people misunderstood his words. They used his statement about destroying the temple as evidence against him. They accused him of blasphemy (Mark 14:58).