Chizuk Emunah (Pt 2) Under the Microscope: Chapter 43

John 2:18-20, "Then answered the Jews, and said unto him [viz., to Jesus], What sign showest thou unto us, seeing that thou doest these things? Jesus answered and said unto them. Destroy this temple, and in three days I will raise it up. Then said the Jews, Forty and six years was this temple in building, and wilt thou rear it up in three days?"

Could Jesus prove his divine character by thus advising the Jews to lay a sacrilegious hand on the sacred edifice? And, moreover, it was most unreasonable to ask that the Jews, who did not believe in his divine power, should commit an action that should consign the temple to everlasting destruction, merely for the sake of testing the reality of his character. 

Troki quotes John 2, but does not quote the whole passage. As John narrates

So the Jews said to him, “What sign do you show us for doing these things?” Jesus answered them, “Destroy this temple, and in three days I will raise it up.” The Jews then said, “It has taken forty-six years to build this temple, and will you raise it up in three days?” But he was speaking about the temple of his body. When therefore 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.
(John 2:18-22) 

John has a habit of rewriting all the dialogue in the style of his own narration, so little in the book of John is a direct quotation of anyone. John is filled with figurative language, telling Nicodemus to be born again, calling himself the door, telling a Samaritan woman that his living water will permanently quench thirst, and telling the crowds to eat his flesh and drink his blood.  People mistook him, and Jesus did not correct them.

The timing of the temple has also been the subject of controversy. Josephus claims that the temple took 8 years to rebuild, or 1.5 years, depending on whether you use book 15 or book 16 of Antiquities as your source. This only refers to the inner cloisters of the temple. Josephus tells us later that the temple was finished in the year 64 under Albinus. According to the Jewish War by Josephus, the renovations began around the year 20 B.C.E. meaning that Jesus gave this statement approximately in the year 26.