The dove/Spirit rests on Jesus, because Jesus is true rest. Just as the dove was sent to find land in Noah’s day, in Matthew the dove rests on Jesus, because he is the true land. In Him there is safety and refuge from judgment; the religious leaders of Jesus’ day did not seek the true land, the true rest, and thus were judged in the Nohaic-like judgment of AD 70.
My guess at the typology of the dive at Jesus’ baptism is that it is a coming together of the creation and new-creation (noah) stories. The Spirit hovers over the face of the waters at creation, the dove hovers over the flood waters. The dove resting over Jesus in the waters of the Jordan indicates not only that he is the Landing place but that a new creation has occurred at his baptism.
very good.