Frank Kuan writes:
So these first 3 similes are really cool, but then we
get to the 4th jhana: ... just as if a man were
sitting wrapped from head to foot with a white cloth
so that there would be no part of his body to which
the white cloth did not extend.

Rene:
I agree with Ven. Thanissaro’s translation here, where he writes “not
extend” rather than “untouched” (Walshe) or “not in contact with” (RD).
(DN 2, par. 82.) The root of the word in question (apphuta.m) seems to
be pharati (spread, suffuse) rather than phusati (touch).

I can’t help you much on the appropriateness of the similes for these
jhanas. But the fact that pharati means both suffuse and extend gives
one an idea of the completeness of the “filling up” with each stage that

is necessary before progressing on to the next.

A schema of the jhanas would be as follows (my rendering):

(1) a state born of detachment,
accompanied by deliberation + reasoned reflection,
delight + contentment.

(2) (suppression of deliberation + reasoned reflection)
continuing delight + contentment
His mind becomes concentrated.

(3) (suppression of delight / and its opposite, disgust)
continuing contentment
He abides mindful and attentive.

(4) (suppression of contentment / and its opposite, dissatisfaction)
None of the original elements continues.
He abides in perfect mindfulness and equanimity,
free from happiness and sadness.

As usual, your comments are appreciated.-- Rene