Matthew 12:39

An evil and adulterous generation. — The true relation between Israel and Jehovah had been represented by the prophets as that of the wife to her husband (Jeremiah 3; Ezekiel 16:23; Hosea 1:2). The adulterous generation was therefore one that was unfaithful to its Lord — demanding a sign, instead of finding sufficient proofs of faithfulness and love in what He had already done.

There shall no sign be given to it. — The words seem at first to place our Lord’s miracles of healing outside the category of signs, and yet it was to these that He referred the messengers of the Baptist as proof that the Christ had indeed come (Matthew 11:5). They must, however, be interpreted by the context. One sign and only one, such as they demanded, should be given to those for whom the other notes of Messiahship were insufficient, and that should be the sign of the prophet Jonas.