Aleph

The numerical value of Aleph is 1.

Aleph means "ox"

According to the Sepher Yetzirah, its correspondences are:

Aleph symbolises G-d as the ultimate singularity. As such it also symbolises G-d as the Creator of the universe (everything proceeds from 1). Because of the intrinsic relationship between numbers and letters in Hebrew, aleph as 1 is the essence of all that exists (all numbers contain 1).

Aleph represents the life force that makes mankind different from the animals and other created creatures. In the Torah (Gen. 2:7) G-d breathed in to the nostrils of the man He had created from dust "and man became a living soul". Here we can see a relationship between the element Air, as designated in the Sepher Yetzirah, and the life force.

This relationship is also demonstrated by a simple gematria:

The Hebrew word for "man" is (aleph-daleth-mem)
If the aleph is removed we are left with (daleth-mem), which means "blood".

Blood gives physical life, but it is the incorporation of the aleph that gives physical life.

Another example of the essential nature of aleph is the word for "truth" (aleph-mem-tau). If the aleph is removed we are left with (mem-tau), which means "death".

Both these examples show the essential life-giving nature of aleph.

Aleph does not have an actual vocalisation associated with it, it is essentially silent. In the meditation associated with the Sepher Yetzirah you are told (at step 3) to alternate between concentrating on the sounds "Mmmmmm" (mem) and "Shhhhhh" (shin). Between these two states there is a point of quietness represented by the unpronounced aleph. On the Tree of Life the movement between the active states of mem and shin via aleph is clearly visible from the positions of their respective Paths:

The Path of mem runs between Netzach and Hod, it is the lowest horizontal Path;
The Path of shin runs between Chokmah and Binah, the highest horizontal Path;
Aleph is associated with the middle horizontal Path from Chesed to Geburah.

This particular prelude to the meditation helps to balance the mind as the it focuses on the three balanced Paths on the Tree.

Aleph represents the highest wisdom and illumination that mankind is capable of experiencing. It is the purity of ideas in all forms of existence.

In the individual person aleph denotes the enlightened mind - reasoning, perception, the realisation of the profoundest truths. It arouses the intellectual faculties.

Aleph can be seen as the central point of all and the abstract principle of a thing.