This aye night, this aye night
Every night and all
Fire and fleet and candlelight
And Christ receive thy soul.
This is the rhyme that Richard kept repeating in his head as he ran after killing the Beast. This is a verse from the song "Lyke-Wake Dirge." "Lyke-Wake Dirge" is a traditional English song that talks about the journey that the soul experiences on its way from Earth to Heaven. Right after this verse in Neverwhere, is the sentence, "The words went around and around, dirgelike, in his head." This is clever because Neil Gaiman uses the word "dirgelike" to describe the words, and in actuality, the words came from a song called "Lyke-Wake Dirge."
For more information on "Lyke-Wake Dirge" visit:
http://en.wikipedia.org/wiki/Lyke-Wake_Dirge
or
http://www.thefreedictionary.com/dirge