English belongs to the Indo-European language tree which has its origin about 4000 BC. Indo-European languages - Wikipedia
Many words have etymology tracing back to 1000 BC or more.
What are some of the oldest phrases/expressions in the modern day English language ?
This is a table of words in most modern Indo-European languages that apparently go back to Proto-Indo-European:
These are names of relatives, body parts, numbers, animals, body functions, mental states, directions, time words, etc. Phrases would be harder to trace back. I don’t know if that’s what you really mean.
Bite the dust
The blind leading the blind
By the skin of your teeth
Broken heart
Can a leopard change his spots?
Cast the first stone
Eat, drink, and be merry
Eye for an eye, a tooth for a tooth
Fall from grace
Fly in the ointment
For everything there is a season
Forbidden fruit
Go the extra mile
He who lives by the sword, dies by the sword
How the mighty have fallen
Pride comes before a fall
Put words in one’s mouth
Rise and shine
See eye to eye
Sign of the times
Straight and narrow
Twinkling of an eye
There’s nothing new under the sun
Wash your hands of the matter
Wolves in sheep’s clothing
The writing’s on the wall
That one actually predates the Bible. The Code of Hammurabi, 1754 BCE, says (in one translation), “If a man destroy the eye of another man, they shall destroy his eye. If one break a man’s bone, they shall break his bone. If one destroy the eye of a freeman or break the bone of a freeman he shall pay one gold mina. If one destroy the eye of a man’s slave or break a bone of a man’s slave he shall pay one-half his price.”
So not exactly the same phrase, but the sentiment is there.
The OP is confusing, because it talks about words with “etymology tracing back,” however, that has nothing to do with a phrase or expression used in today’s English which is just a translation of something from an old text in another language.
All of those expressions that Walken after Midnight lists from the Bible were not written in English. They’re just translations, and are not “traced back” to to anything. So I don’t see the point of the first two sentences in the OP.
I remember the Guinness Book of Records 1980 edition had an entry for oldest words in the English language. There were four words listed of which I am pretty sure two were “apple” and “gold”. Is there any basis for this claim? Are these words thought to be older than other PIE roots?
Ther nis no werkman, whatsoevere he be, That may bothe werke wel and hastily.
Geoffrey Chaucer 1343-1400
Researchers found that the frequency with which a word is used relates to how slowly it changes through time, so that the most common words tend to be the oldest ones.
For example, the words “I” and “who” are among the oldest, along with the words “two”, “three”, and “five”. The word “one” is only slightly younger.
Proto-Indo-European *yū and Modern English you: pronunciation and meaning both completely unchanged for 5,000 years.
You could make a case for *sem- and same having the same pronunciation and meaning. There are plenty others on the list that are really close, like *webh- and web, *bher- and bear (carry)
I expect most, if not all, those Biblical phrases didn’t become common phrases or idioms in English until many people had a chance to read it in English. That would likely be sometime in the 16th-17th centuries.