Therefore tongues are for a sign, not to those
who believe but to unbelievers; but prophesying is not for unbelievers but
for those who believe. 1 Corinthians 14:22 (NKJV)
For the Jews require a sign, and the Greeks
seek after wisdom: 1 Corinthians 1:22 (KJV)
For with stammering lips and another tongue
will he speak to this people. Isaiah 28:11 (KJV)