Contradiction with Deuteronomy 6:16
This verse instructs not to test the Lord, whereas Isaiah 7:11 invites asking for a sign from God, which could be seen as testing Him.
Deuteronomy 6:16: Ye shall not tempt the LORD your God, as ye tempted [him] in Massah.
Contradiction with Matthew 4:7
Jesus quotes this to reinforce that one should not test God, contrasting with the directive in Isaiah 7:11 to ask for a sign.
Matthew 4:7: Jesus said unto him, It is written again, Thou shalt not tempt the Lord thy God. [tempt: or, try, or, put to trial, or, proof]
Contradiction with Matthew 12:39
Jesus refuses to provide a sign to the Pharisees, suggesting that seeking signs is contrary to faith, unlike the open invitation in Isaiah 7:11.
Matthew 12:39: 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:
Contradiction with John 20:29
Emphasizes blessedness in believing without seeing a sign, in contrast to Isaiah 7:11, which invites a sign to be requested.
John 20:29: Jesus saith unto him, Thomas, because thou hast seen me, thou hast believed: blessed [are] they that have not seen, and [yet] have believed.