A practical example is the Gemara BT Rosh Hashana 26b which discusses the meaning of obscure Hebrew words, which the Hahamim were able to derive from listening to the regular speech of servants and others; Rabbi's maid, for example:
לא הוו ידעי רבנן מאי סירוגין שמעוה לאמתא דבי רבי דחזתנהו רבנן דהוו עיילי פסקי פסקי אמרה להו עד מתי אתם נכנסין סירוגין סירוגין לא הוו ידעי רבנן מאי חלוגלוגות יומא חד שמעוה לאמתא דבי רבי דחזית לההוא גברא דקא מבדר פרפחיניה אמרה ליה עד מתי אתה מפזר חלוגלוגך לא הוו ידעי רבנן מאי (משלי ד) סלסלה ותרוממך יומא חד שמעוה לאמתא דבי רבי דהוות אמרה לההוא גברא דהוה קא מהפך בשעריה אמרה ליה עד מתי אתה מסלסל בשערך לא הוו ידעי רבנן מאי (ישעיהו יד) וטאטאתיה במטאטא השמד יומא חד שמעוה לאמתא דבי רבי דהוות אמרה לחבירתה שקולי טאטיתא וטאטי ביתא לא הוו ידעי רבנן מאי (תהילים נה) השלך על ה' יהבך והוא יכלכלך אמר רבה בר בר חנה יומא חד הוה אזלינא בהדי ההוא טייעא הוה דרינא טונא ואמר לי שקול יהביך ושדי אגמלאי
The Rabbis did not know what was meant by serugin, until one day they heard the maidservant of Rabbis household, on seeing the Rabbis enter at intervals, say to them, How long are you going to come in by serugin?
The Rabbis did not know what was meant by halugelugoth, til one day they heard the handmaid of the household of Rabbi, on seeing a man peeling portulaks, say to him, How long will you be peeling your portulaks? (halugelugoth).
The Rabbis did not know what was meant by, salseleah (and it shall exalt). One day they heard the handmaid of the house of Rabbi say to a man who was curling his hair, How long will you be mesalsel with your hair?... [Then comes a similar example which does not involve Rabbi Judah’s maidservant. I
The Rabbis did not know what was meant by we-tetethia bematate (of destruction), til one day they heard the handmaid of the household of Rabbi say to her companion, Take the tatitha (broom) and tati (sweep) the house.
The Rabbis did not know what was meant by Cast upon the Lord thy yehab and he shall sustain thee. Said Rabbah b. Bar Hanah: One day I was travelling with an Arab and was carrying a load, and he said to me, Lift up your yehab and put it on [one of] the camels.
What does this Gemara take for granted and what, perhaps, doesn't it take for granted? I would say it takes for granted that Hebrew was used in regular conversation among servants--or perhaps this servant was the last of the (naturally Hebrew speaking) mohicans, so to speak.
But what is not taken for granted is that the speech of maids can teach us what words in the Bible mean. The former is incidental to the story, the latter is the point of it. Therefore we can know something about spoken Hebrew from this story. What precisely that is? We need to be cautious and we need to examine other evidence. But one thing is clear: it is taken for granted that such a person spoke such a dialect. Thus, we can safely assume it to be reflective of the true situation and we now know something about spoken Hebrew in Rabbi's time, although dating the story is another matter; in theory it could be from a later time when it was assumed that the vernacular of maids in an earlier period was Hebrew. But the salient point is that the incidental information which the story-teller takes for granted tells us things.
If I am not mistaken, this principle was applied by Saul Lieberman in many of his studies on talmudic-era Israel in the Greco-Roman world, in his analysis of both rabbinic texts and non-Jewish sources.
So I thought I'd apply this same principle to determine something about R. Dr. Lieberman himself.
First, the background. In the biography of Saul Lieberman by Spiro and Schochet (pp. 175-76) one find the following distillation of his attitude towards modern scholarship in the service of Torah study, how necessary it is:
In his introduction to Tosefta Kifshuta, Zera'im, Lieberman acknowledges his indebtedness to the early commentators: "the first pioneers ... upon whose shoulders we stand and from whose wine we drink." Lieberman attributed errors on their part to the conditions of their time and to the lack of manuscripts that are available today. In particular, Lieberman calls our attention to the difficult working conditions of Moses Samuel Zuckermandel, the first scholar to publish a scientific edition of the Tosefta. Yet, in the interest of truth, Lieberman points out the limitations that constrained the scholarship of previous generations.
- They possessed little knowledge of the Greco-Roman world.
- They failed to understand or appreciate the uniqueness of the Talmud Yerushalmi's style and language.
- They failed to appreciate how the traditions of the Jews of Palestine differed from those of Babylon.
- They lacked manuscripts of the Talmud Yerushalmi.
- They did not pay sufficient attention to gaonic writings in order to determine accurate texts of the Talmud Yerushalmi.
In short, a perfect manifesto about the need fo using modern scholarly methods to properly understand the Talmud Yerushalmi (and Tosefta).
On page 190-91 of the book, we are given an abstract of a speech R. Dr. Lieberman gave called "A Talmud Written by the People in Their Own Land:"
He "listed the publication of the Escorial manuscript of the Palestinian Talmud Nezikin as one of the '[t]hree important events [that] have taken place in the last two years with regard to the Palestinian Talmud. First, a very important manuscript was discovered by the late Professor Rosental [sic] of blessed memory of the Hebrew University, a manuscript of a part of the Talmud that will greatly enhance our knowledge and understanding of the Talmud in general. Second, a concordance of that Talmud is now being published in Jerusalem by the Israel Academy of Sciences and the Jewish Theological Seminary of America....Third, an international assembly of Orthodox rabbis has suggested that the Palestinian Talmud should be studied daily by all Jews who study the Babylonian Talmud.
Now, I'm not sure what exactly this tells us about his relationship with Orthodoxy, but I am suggesting this tells us something of his scale of values. To him, an important manuscript of the Yerushalmi, a concordance of the Yerushalmi and a call to study the Yerushalmi daily by Orthdox rabbis were important events.
Critics from a right-leaning perspective are probably not too impressed by this, but I think it incidentally imparts something about how he balanced his scales. (Not that this is surprising to those who knew him, by every account.)