Need help understanding this
That is an effect of dasavidhaappanākosallaṃ, that appear before your quote.

My link is just a head. There is more information in that book after the head.

For a guideline:

Beginning = complete and perfect practicing of all dasavidhaappanākosallaṃ (achieved jhāna). 

Middle = an effect of the 7th of dasavidhaappanākosallaṃ.

End = an effect of the 6th of dasavidhaappanākosallaṃ.

You must memorize dasavidhaappanākosallaṃ head, and meditate it to get a deep understanding.

Note: I never read throughout the english translation version (my english is terrible), that make me not sure about the translation's quality. So you can ask more, if you see something that is unclear.