This is what I was referring to in the other post.
Y: "The word jhaana is a neuter noun, so 'jhaano' is rather
incorrect...unless, as in this case, arittajjhaana is used in the
sense of an adjective qualifying bhikkhu, hence 'arittajjhaano'."
If the adjective qualifies "bhikkhu" then this refers to the person
who must keep something in mind, and perhaps not to total jhaana all
the time.