It's as if the commodity of the bride is deemed truly valuable only if it can be guaranteed pure and untouched.

这就好像新娘这件商品,只有在完全的纯净没有动过才是有真正价值的。

耶鲁公开课 - 弥尔顿课程节选

And Milton, or the Elder Brother here, is clearly thinking of Revelation 14, in which it's only the pure spirit or the virgin -- that can even begin to hear the new song being sung before the throne of God.

弥尔顿，或者大哥，显然说的是《启示录》第14章的内容，那里说只有纯净的精神或有童贞,才可以听到在上帝面前唱的新歌。

耶鲁公开课 - 弥尔顿课程节选