The word for “letter” is אות. Let’s break down this word and see what we get.
The letter alef represents godliness and the highest level of spirituality. We see this from the fact that the letter א has a gematria of one, and He is called 'האחד, Hashem the One (and Only). Also, the first letter of אחד is an alef.
Furthermore, many names and descriptions of Hashem begin with א: א-ל, אלה-ים, אדיר, אחד, אדנ-י and אהי-ה.
The Ben Yehoyada teaches that the letter א is formed from a ו and two יs. Adding these letters up, we get a sum of 26, the gematria of י-ה-ו-ה.
If the alef symbolizes the highest level of spirituality, then the furthest letter from alef symbolizes the lowest point—tav. Just as the farther you move from the sun the colder it becomes, so too the distance from alef reflects spiritual descent. Fittingly, the first time the letter tav appears in the Torah is in the word תהו, the realm of chaos.
Now, let’s move onto the letter vav. The letter ו is a connector as it means “and.” Additionally when ו is spelled out it spells וו which means a hook, that which connects.
We know that Hashem brought existence into being through the letters of lashon hakodesh when He spoke as it says בעשרה מאמרות נברא העולם, Hashem created the world with ten utterances. In similar vein, we say in shacharis ברוך שאמר והיה העולם, Blessed is He Who spoke, and the world came into being.
With all that we mentioned we can now explain in a deeper way the word אות, letter. A letter is a spiritual force (א) that Hashem bound (ו) to form the physical (ת). This is what the lashon hakodesh letters did, as they brought the different parts of the physical world into existence.
