I believe it's from the Bible's Old Testament, and a book often referred to as the Book of Solomon, or Wisdom of Solomon, Chapter 5. In the context of Munrow's untimely death it makes for very poignant reading:
Wisdom Chapter 5
The fruitless repentance of the wicked in another world: the reward of the just.
5:1. Then shall the just stand with great constancy against those that have afflicted them, and taken away their labours.
Tunc stabunt iusti in magna constantia adversus eos qui se angustaverunt et qui abstulerunt labores illorum
5:2. These seeing it, shall be troubled with terrible fear, and shall be amazed at the suddenness of their unexpected salvation,
Videntes turbabuntur timore horribili et mirabuntur in subitatione …