Hi Steve:

Your source phrase is 100% of Filipino origin, but is more Cebuano (or Visayan) than Tagalog. The operative word here is the verb "pahuway". Definitely, "pahuway" is not used in conversational or even formal Tagalog, whether in Manila or in the surrounding suburbs and provinces. However, in the southernly Cebuano language, pahuway means "to rest" or "to take a nap" or "to sleep."

Thus, please note the word-per-word translation below:

Pahuway = "to take a rest"
ka na lang = "you just"
sa = "in" or "at"
banga = "jar", esp. a big clay jar that can hold anywhere from a few gallons of water to an entire wardrobe or a collection of family treasures.

Thus, the entire English translation would be "You just take a rest there in/at/by the jar."

Probably this is idomatic, or expressed jokingly, as in "go take some time out inside that jar". On the other hand, it may just mean "You may take a rest near that jar."

It is unlikely that this comment means anything bad :)

Hope this helps!

Perhaps, already lost in the historical memory..The usage of this phrase hails back to ancient Malays/Bornean- Filipinos. It is derived from the Visayan dialect. Ancient Filipinos were known to have a practice of burying/keeping their dead inside the jar.


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Note added at 3833 days (2012-07-18 19:51:49 GMT)
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Now this phrase is a figure of speech, an idiomatic way of telling someone who is discontented with life and is incessantly complaining to snap -out of it -( to a child or daughter maybe, or sister, etc) .."pahuway ka na lang sa banga!" just like our modern day version of saying "tumalon ka na lang sa dagat! (in tagalog meaning jump in the sea/river/lake!) or "magpatuka ka na lang sa ahas! (let the snake bite you! ala Cleopatra of Egypt)