American Standard Version (ASV):
Wherefore tongues are for a sign, not to them that believe, but to the unbelieving: but prophesying [is for a sign], not to the unbelieving, but to them that believe.
King James Version (KJV):
Wherefore tongues are for a sign, not to them that believe, but to them that believe not: but prophesying [serveth] not for them that believe not, but for them which believe.