Missional Jesus continues to be opposed; he keeps on walking.
The context is evidently the belief that the Messiah would be accompanied by signs that proved Messiahship.
1. Missional Jesus is opposed to empirical proof being needed to reveal who he was.
2. Missional Jesus reveals that the only sign he cares to give is the “sign of Jonah,” which has been rendered in all sorts of ways — but the most likely one remains what Matthew 12:40 provides: “For just as Jonah was three days and three nights in the belly of the sea monster, so for three days and three nights the Son of Man will be in the heart of the earth.”

3. Missional Jesus reveals that his sign is and will be his death and resurrection. These reveal who he was and is and will be.
Matt. 16:1 The Pharisees and Sadducees came, and to test Jesus they asked him to show them a sign from heaven. 2 He answered them, “When it is evening, you say, ‘It will be fair weather, for the sky is red.’ 3 And in the morning, ‘It will be stormy today, for the sky is red and threatening.’ You know how to interpret the appearance of the sky, but you cannot interpret the signs of the times. 4 An evil and adulterous generation asks for a sign, but no sign will be given to it except the sign of Jonah.” Then he left them and went away.