John 2:18-22

18 Then answered the Jews and said unto Him, What sign shewest Thou unto us, seeing that Thou doest these things?

19 Jesus answered and said unto them, Destroy this temple, and in three days I will raise it up.

20 Then said the Jews, Forty and six years was this temple in building, and wilt Thou rear it up in three days?

21 But He spake of the temple of His body.

22 When therefore He was risen from the dead, His disciples remembered that He had said this unto them; and they believed the Scripture, and the word which Jesus had said.

The Jews challenged Jesus to do a miracle to prove He had the authority to clear the Temple. He offered the sign of His own resurrection.

Jews require a sign — For the Jews require a sign, and the Greeks seek after wisdom (1 Corinthians 1:22). But they still didn’t believe in spite of all the miracles Jesus did.

Then certain of the scribes and of the Pharisees answered, saying, Master, we would see a sign from Thee. But He answered and said unto them, An evil and adulterous generation seeketh after a sign; and there shall no sign be given to it, but the sign of the prophet Jonas: For as Jonas was three days and three nights in the whale’s belly; so shall the Son of man be three days and three nights in the heart of the earth (Matthew 12:38-40).

Christ’s words were twisted and used as an accusation against Him before Caiaphas — And [they] said, This fellow said, I am able to destroy the temple of God, and to build it in three days (Matthew 26:61).

Jesus told the disciples that He would send the Spirit who would remind them of what He had taught. But the Comforter, which is the Holy Ghost, whom the Father will send in My name, He shall teach you all things, and bring all things to your remembrance, whatsoever I have said unto you (John 14:26).

Scripture (verse 22) —The body of Old Testament Scripture prophesying the resurrection.