It's a provisional ending. It's not a rhyme word, and so it doesn't constitute the end of a unit of sense as a rhyme word would in most heroic couplets.

它不是真的结尾，不是韵脚，因此它不像大部分英雄双韵体中的韵脚词一样,标志着一个意思表达的完结。

耶鲁公开课 - 弥尔顿课程节选