What is “Midrash” and how does it relate to Christian principles of hermeneutics?

From the perspective of Sensus PLenior:

When Jesus was 12 he taught the teachers how to read the scriptures in a way they had never seen before. As a Jewish child he was taught to ask "What are these stones, referring to a pile of rocks by the water. But instead he asked about the cleft in the rock where Moses hid, and the five smooth stone which David put in his "shepherds pouch", the stone that gave water, etc. Since God said that he was the rock...

   De 32:4 He is the Rock, his work is perfect: for all his ways are judgment: a God of truth and without iniquity, just and right is he.

   De 32:18 Of the Rock that begat thee thou art unmindful, and hast forgotten God that formed thee.

   1Sa 2:2 There is none holy as the LORD: for there is none beside thee: neither is there any rock like our God.

   2Sa 23:3 The God of Israel said, the Rock of Israel spake to me, He that ruleth over men must be just, ruling in the fear of God.

...the boy Jesus would say that all the rocks spoke of God.

SP says that the teachers saw the hidden pictures of the Messiah for the first time.

According to this doctrine, over the next 18 years they perverted the method so that when Jesus began his teaching, they would not lose their control over the people. This is why they were called 'vipers' not misguided teachers: they knew the truth but lied about him.

Midrash and Sensus Plenior use the same methods of solving riddles, but Sensus Plenior adds consideration of Jesus as an answer. In the parable of the four rabbis they were warned: "When you see the white rock, don't say water, water". In sensus plenior, Jesus is the White Rock, and "Water, water" means the "Word of God in heaven and on earth".

The apostles use the methods of Sensus Plenior as their focus is ALWAYS on Christ.