Contradiction with Numbers 23:19
This verse emphasizes God's unchanging nature, while Zechariah 8:14 speaks about God changing His mind regarding affliction.
Numbers 23:19: God [is] not a man, that he should lie; neither the son of man, that he should repent: hath he said, and shall he not do [it]? or hath he spoken, and shall he not make it good?
Contradiction with 1 Samuel 15:29
This verse states that God will not repent or change His mind, contrasting with Zechariah 8:14 where God repents from punishing.
1 Samuel 15:29: And also the Strength of Israel will not lie nor repent: for he [is] not a man, that he should repent. [Strength: or, Eternity, or, Victory]