John 2:19 Jesus answered and said to them, “Destroy this temple, and in three days I will raise it up.”
After clearing the physical temple of all the people who had treated it with disrespect and ignoring God, Jesus gave these words to His disciples.
The temple He was talking about was not the physical building but rather at His body; but this would not come to light until much later.
Jesus was keeping to the promises made many years ago and was at this time promising something which would come a few years later.
Trust in a God who always fulfils His promises!