In 'Ask the Rabbi' issue #121, Case E. Krell asked why there are no vowels written in the Torah.
We offered a few answers, including the idea that the Torah's words can be understood in many different ways. Writing the vowels would limit the different ways the Torah can be read.
Since then, Rabbi Zev Rosen directed me to a very interesting source describing the 13 Torah scrolls that Moses wrote. At the end of his life, Moses wrote 13 Torah scrolls. He gave one scroll to each of the twelve tribes, and the thirteenth was placed in the Holy Ark. According to some, this thirteenth scroll was indeed written with vowels and accent marks.
[Please see "Ask the Rabbi" Issue #121 for more details. See also Rabbeinu Bachya, Devarim 7:2, and Bereishit 18:3. (Thanks to Yaakov Schwartz for this source.)]
- Rabbi Aryeh Kaplan, Handbook of Jewish Thought, Ch. 7 footnote 136 citing Tzafanat Pa'aneach, Devarim 31:9. He adds, "This may be supported by Bahir 115, which speaks about the "vowels in the Torah of Moses."