ESV: And if you say in your heart, ‘How may we know the word that the Lord has not spoken?’ —
NIV: You may say to yourselves, "How can we know when a message has not been spoken by the Lord?"
NASB: And if you say in your heart, ‘How will we recognize the word which the Lord has not spoken?’
CSB: You may say to yourself, ‘How can we recognize a message the Lord has not spoken?’
NLT: But you may wonder, ‘How will we know whether or not a prophecy is from the Lord?’
KJV: And if thou say in thine heart, How shall we know the word which the Lord hath not spoken?
NKJV: And if you say in your heart, ‘How shall we know the word which the Lord has not spoken?’—