5:19 The word for quench is "sbennu-mi." This has a rather unclear English cognate: asbestos. (asbestos is something that is unquenchable!)
5:23 Two of the words here have the root "holo" (as in 'whole'). In English the breadth of Paul's statement about spirit, soul and body is clear; the Greek words just accent this a bit. The NRSV drops the second "holo" word which modifies "spirit."