Why are the Dead Sea Scrolls (DSS) significant?

Question

Is there anything that the Dead Sea Scrolls made clearer regarding the texts of the Old Testament? Did their discovery change the way we view the development of the Tanakh?

Answer 1

I think I may be posting an answer not quite in-line with what you were hoping for but I am not sure if anyone has published the various differences between the manuscripts that could answer your question properly. I apologize about that.

However, I think it might be worth mentioning that the main benefit of the Dead Sea Scrolls is not small clarifications here and there but that they provide a very large portion of the Old Testament scriptures that are older than those previously extant without 'hardly any difference'.

The scrolls are many:

Over six hundred scrolls and thousands of fragments have been discovered in the 11 caves of the Qumran area. Fragments of every Biblical book except Esther have been found, as well as many other non-Biblical texts. (Source)

The scrolls show how well the scriptures have been preserved to us today without any difference:

One of the most important contributions of the Dead Sea Scrolls is the numerous Biblical manuscripts which have been discovered. Until those discoveries at Qumran, the oldest manuscripts of the Hebrew Scriptures were copies from the 9th and 10th centuries AD by a group of Jewish scribes called the Massoretes. Now we have manuscripts around a thousand years older than those. The amazing truth is that these manuscripts are almost identical! Here is a strong example of the tender care which the Jewish scribes down through the centuries took in an effort to accurately copy the sacred Scriptures. We can have confidence that our Old Testament Scriptures faithfully represent the words given to Moses, David and the prophets. (Source)

Answer 2

They also show us that the canon was settled long before Jamnia. In the scrolls, we have at least partial copies of every book in the Old Testament except Esther. We also have many scrolls that are not canonical, however, even that teaches us something. Their literature can be broken down into three types. (The percentages are from my seminary notes with Dr. Waverly Nunnally who studied at Hebrew University in Jerusalem and Hebrew Union in Cinncinatti. His dissertation was on the use of Abba in the Dead Sea Scrolls, and he and his best friend wrote a computer program to reconstruct the scrolls from a concordance before their public release.)

1. Old Testament manuscripts. Dt., Is, and Ps are the most frequent and quoted most often in the sectarian texts. The New Testament and rabbinic literature quote those three the most and in about the same frequency as Qumran. We have pieces of every book in the Old Testament except Esther (but we don’t have everything from Qumran). This makes up 12% of the texts.

2. Apocrypha and Old Testament psuedopigrapha. This category is very important in what it teaches us. It was assumed by some scholars that these apocryphal and pseudopigriphal works had origianlly been written in Hebrew, but until this, no evidence outside of the text (the Greek copies contain many Hebraisms, phrases that look like they were originally Hebrew or written by someone whose first language was Hebrew). Text critics and translation theorists loved this find. Examples from this category were ~66% of Ecclesiasticus and two versions of Tobit (and the longer version is the older of the two). These works make up 3% of Qumran.

3. Secterian Material. These works are unique to Qumran and the Essenes. Examples of this would be Community Rule, War Between the Sons of Light and the Sons of Darkness, and the letter they wrote to the Pharisees (MMT). Two things it shows us is that they considered themselves to be the true remnant and believed that the temple was broken. 85% of the material falls into this category.

The Essenes wrote a style of commentary called Pesher. All such Pesher falls into category 3. There are three ways that they show us the Old Testament was settled before Jamnia.

1. They only write Pesher on canonical works. I do not have the breakdown on which books they wrote Pesher on, but they only wrote it on canonical works.
2. Even though many other apocryphal and pseudopigraphal works were available, they collected 4 times as many canonical works.
3. In the letter to the Pharisees (MMT), they specifically state, "these are the books we hold to be sacred..." They then state the three divisions of the Old Testament, "book of Moses," "the word of the Prophets," and "David and the Events of the Days of All the Generations." David, of course, refers to Psalms, the first and largest book in the writings. Events of the Days is another name for Chronicles, the last in the set. The natural conclusion from this is that if they name the same divisions as are used even today, and as we can be sure that the books of Moses counts five and not six or seven, and the writings begins and ends with the same books as later, then the canon was already settled.