“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:”
King James Version (KJV)
12:39 An adulterous generation - Whose heart wanders from God, though they profess him to be their husband. Such adulterers are all those who love the world, and all who seek the friendship of it. Seeketh a sign - After all they have had already, which were abundantly sufficient to convince them, had not their hearts been estranged from God, and consequently averse to the truth. The sign of Jonah - Who was herein a type of Christ.
Mt 12:39 An evil and adulterous generation. We must keep in mind that the Lord is speaking to his enemies. He compares them to a faithless wife. They were faithless to God. See Mt 16:4. The sign of the prophet Jonah. See Mt 12:40.