NOTES for Mat 12:38-42
Today we understand the word "sign" as a miracle. Yet the corresponding Greek word, and also "sign" in its original meaning, which it has in Church Slavonic or Old Russian, means a "mark" or "signal." It turns out that the people listening to Jesus expect from Him some kind of sign that would speak... about what, exactly? About His messiahship?
That is quite possible: as people thought in those days, when the Messiah came, He had to prove His messiahship, including by certain definite signs, among which there had to be miracles, manifestations of God's power proving that God was truly with Him and that He was entrusting Him with the ministry to which He laid claim. More broadly, signs were expected in order to be convinced that it was truly God acting, and not a person acting by his own will. Such signs were expected and demanded from Jesus: by them His listeners wanted to determine who He really was before them. The demand would seem quite legitimate, if not for one "but": Jesus had shown more than enough testimony that God was truly with Him, as He tells the people around Him.
Israel had never before seen such manifestations of the Kingdom, of its breath, of its power, such visible signs of God's presence, and many who looked at the situation without prejudice agreed with this. Of course, the signs were not exactly the kind people expected, but they were plainly there. Many people's unwillingness to see the obvious made new signs meaningless: those who wanted to see had already seen, and those who did not want to see would not have seen anything, no matter what signs were shown to them. There was, however, something else as well: fascination with signs does not always bring a person spiritual benefit in itself.
A sign is only a pointer to the main thing; it must not become something self-sufficient and self-important. Signs are like a geographical map that depicts real terrain schematically: on different maps the system of symbols may differ, but if the map is accurate, it will in any case convey the geographical realities adequately. To reject a map with an unusual system of symbols merely because that system is unfamiliar means forgetting the purpose of a geographical map as such. That is why Jesus does not try to conform to the public's expectations concerning signs: what matters to Him is the Kingdom, not the pointers.