Surprise - It's a machloket! This machloket is at least 1,800 years old, and we at Nishmablog are not going to resolve it in a Blog Post or 2
But it does make for a fascinating topic re: Talmudic rulings and "scientific evidence"
This post was triggered by a lively discussion on the Leining Google Group.
Below are some hits from a Google search:
In terms of what script was used at Mount Sinai, there is a 3 way disagreement in the Talmud Sanhedrin 21b-22a.
Mar Zutra (some say it was Mar Ukva) holds that the Torah was originally given in Ivri script, but later the standard was changed to Ashuri in the times of Ezra.
Rebbi says that it was given in Ashuri script, but after the Jews sinned (not clear which sin is referred to) it was switched to Ivri script. Later when they repented it switched back to Ashuri script.
Rav Elazar HaModai says it was always in Ashuri script, and Ivri script was likely just a common handwriting used by the people but not in Torah scrolls.
Which alphabet were the original Torah scrolls in? - Mi Yodeya
Script and Vowelization
Although the "Old Hebrew" script was commonly used in ancient Israel, the original Torah scrolls, as well as the Tablets of the Ten Commandments, were written in the same Ashurit script used for Torah scrolls today. According to other opinions, however, the Ashurit script was forgotten during the Babylonian exile, and the common Old Hebrew script was used for Torah scrolls, until the Ashurit script was restored by Ezra. A third opinion is that the Torah and Tablets were originally given in the Old Hebrew script, and the Ashurit script was introduced by Ezra.
The original Torah scrolls were written without vowels, just as they are written today. However, just as the exact text of the Torah was given to Moses, so were the precise readings. These were preserved orally until they were finally put in writing.
Writing the Torah
Was the Torah written originally in Phoenician or Paleo Hebrew script?
Modern Hebrew called Ktav Ashuri, came from Assyria. The Torah was first written in Ktav Ivri, which is either Phoenician or Paleo Hebrew. There are small differences between the two scripts. Which one was etched in stone at Sinai?
Asked by Christopher 5 years ago
It is most likely that the original Torah was written in Ivri script. The two Talmuds disagree on the script used in the original Ten Commandments with one implying Ivri and the other Ashuri. At any rate, they have the same letters in the same order. They are written differently. Phoenician and Ivri are very similar and one who is trained in reading one can read the other.
Was the Torah written originally in Phoenician or Paleo Hebrew script? - Y! Answers
This second professor suggests that the Hebrews spoke Egyptian in Egypt so the question remains "Why was the Torah given in Hebrew"?
I then sent the question to a rabbi with a PhD from Cambridge in Philosophy and S'micha from Mir Yeshiva. This is his reply:-
"Archaeological evidence shows that a Hebrew Language was in use around 3000 years ago and inscriptions around 700 BCE are in the public domain. The Samaritan Torah is still written in the early Hebrew script. Judaism changed to our current (square) script in Babylon. You can see these scripts on Google. As to what the Torah was written in, it certainly wasn't originally given the square script we now have."
This rabbi dates Hebrew very early but does not deal with the language that the Hebrew spoke in Egypt".
Was the Torah written in Hebrew | Reflecting on Judaism