Skin of his teeth is from the Bible and is an english translation from Hebrew. It simply means 'by a narrow margin' (derived from the fact that the coating of our teeth is very thin).
I've never found a definitive explanation of no skin off my nose . My guess is it's dervied from the following:
(1) The phrase means 'it doesn't matter to me, since it hasn't and will not cause me any inconvenience'.
(2) Skin coming off your nose as a result of a scrape or sunburn is not pleasant. But if you don't experience this, then clearly it isn't a problem.
(3) Hence, not having a particular problem is analagous to not having skin coming off your nose.
Keep your eyes peeled 'Peeled' in this case simply means to keep your eyelids open - i.e. it's an instruction to remain observant and not fall asleep.
Save your neck refers to the days when capital punishment by hanging was commonplace. The UK abolished the death penalty several decades ago, but at one time hanging was a common punishment for even trivial offences (e.g. stealing an article worth over 5 shillings [even back then this was a fairly small amount], kicking London Bridge or impersonating a Chelsea Pensioner). Thus, 'saving your neck' means to escape serious punishment. Save your skin is probably derived from the analogy of a killed animal being skinned.
In Chelsea (a district of London) in the 18th century (I think) a large residential home was built to house veterans of the British armed forces who had been of exemplary character in their years of service and who in old age had fallen on hard times. These people rapidly became known as Chelsea Pensioners and have a characteristic uniform of a long red overcoat, black trousers and shoes. There were various perks associated with being a CP (free food, free admittence to various events, etc). Hence, impersonating a CP could be lucrative (though hardly worth punishing with the death penalty).
The institution, I'm pleased to say, is still going. There are still perks (e.g. the local soccer club - called Chelsea, not surprisingly - to its great credit gives the CPs free seats for home matches; the annual Chelsea Flower Show, which is a big gardening and social event in the UK is held in the grounds and the CPs get priviledged access prior to the official opening). I don't think the 'fallen on hard times' criterion is quite so rigid these days, but CPs still have to be widowers or single to gain admittance, I believe.
Uh, I believe the original saying is/was, "Keep your eyes open and your ears peeled", a reference to how animals (particularly predators) make their protruding ears fold back when they're on the hunt and in the chase. Ordinary dogs do this---they "peel back" their ears---, for example, when they start to sneak up on squirrels in the park, just before the outright chase.
The modern version of the expression has simply been "collapsed". The fact that it is "acceptably interpreted" by today's native speakers means that the expression to peel one's ears (back) is obsolete and, so, speakers can by analogy substitute the names of other parts of the body---here, other sense organs---into the expression, where the concept of 'attentive perception' is not violated.
Rex - your explanation is possible (I think that there is a dispute over whether the phrases arose independently, but I can't swear to that, and my textbooks aren't to hand). In any case, I was conflating my explanation with the similar phrase of 'keep your eyes skinned'.
I always felt that "coming back like a bad penny" was less sinister than trying to pawn off a counterfeit, but rather dealt with the idea of getting stuck with a penny that was no good (like a Canadian penny). You slip it into your spending to get rid of it, but low and behold it shows up in some change you get a few days/weeks later, ie it keeps getting to you.
You try to rid yourself of something, but it keeps finding its way back to you. Foreign coins are the best examples for "bad penny", though I imagine this could fit for very damaged or dirty coins, like a copper penny that got wet and turned green.
I've always thought this was in reference to the envelopes of air that build around/in front of a jet coming close to the speed of sound, and science was pushing that envelope to its limit in an attempt to break through it.
Since the breaking of the sound barrier was a big deal at the time it would have been discussed in many quarters and this would likely mean the repeating of the envelope analogy when explaining the situation to reporters/general public.
Don't know the meaning, but sounds like the coda (standard ending) of an "old wives' tale" to me. The context is totally lacking, so interpretation is totally ambiguous. Was there a further context? Was this said in response to something you had said to him, or his/her comment on some event that had just occurred which he was basing this on as some sort of "morale of the story"? (". . . . So, you see, Billy, 'Curiosity killed the cat'.")
There're tales there behind many of such sayings. They've just been forgotten---wiped from the cultural repertoire---after some time of not being repeated, because the associated sayings have come to be used as cultural mnemonics---signifying short hand for the whole stories---for so long.
I haven't seen this one mentioned yet (surprisngly), but why is the phrase "what's good for the goose is good for the gander" so popular? WTF is a gander?
And, working retail, I firmly believe this saying doesn't make sense: "The customer is always right." That's the funniest thing I've ever heard. The customer is rarely right, in my experiences. I like the quote from new hire training at the first store I ever worked at: "The customer is not always right, but is always the customer" meaning you can tell the customer they're wrong, but they're still your customer so be nice about it. Definitely much more true than the more popular saying.
This is not a "popular saying", not a statement of fact, but a business slogan meant to convey to customers and the employees serving them that the customer and his concerns come first. And I might add that my experiences with retail employees in recent years definitely tells me they're NOTgetting the message!
With the new ex-Soviet ownership, will this sentiment change in future? After all, a single home-ticket at the Bridge these days must cost at least 50 quid.
I believe the phrase comes from engineering, and long pre-dates the race to break the sound barrier. In engineering terms any device, machine or system operates within certain parameters which can be plotted visually. The shape that a graph based on the performance data takes can be roughly rectangular, which led to its being dubbed the performance "envelope" - because whatever is being discussed operates "inside" the shape formed in the graph.
Since engineers tend to be conservative, both tempermentally and for safety reasons, the normal or safe operating parameters for a given device or system will be well short of its physical capabilities. (A submarine, for instance, is usually physically capable of diving beneath its "test depth", but nobody wants to find out exactly how much deeper by actually trying it. )
Therefore you are "pushing the envelope" when you operate something (including a plane or a car) at, near or beyond its normal or safe operating parameters.
If this version is correct - and I believe it is - the term has nothing to do with literal "envelopes" at all, and it makes perfect sense in the context in which it originated.