What distinguishes the letter yud is that it is a kind of point. The Zohar calls this the nekuda kadma’ah, or original point. (Zohar 1:16b).
In modern language we might call this the first cause or primal point. Making use of modern scientific concepts, we could say that the letter yud represents the singular-point from which the big bang originated. Within this point, which precedes dimensions in space or time, all of existence was held in total unification – and this is represented by the little letter yud. This is the point which began everything, the point that precedes everything that will unfold from within it.

Total Potential
If every created thing has a starting point from which it is created, we can say that each of us, too, has a “yud” from which we are formed. Each person’s body unfolded from the extraordinary original cell which was created when the sperm and the egg of our parents fused. There, within that first cell, which in modern science we call a ‘Totipotential Stem Cell’ our personal unique DNA was first expressed. Basically everything that we will become is already hinted at in that primary, original point, which has the unique ability to split and develop into each and every cell of our bodies. This is why this cell is called Totipotential: it has total potential. This original stem cell is our personal letter yud.

In the month of Elul we are called, in the mystical understanding, to return to that original cell, with its power of extraordinary potential, from which we come to be woven into form in this world. Modern science reveals to us that these original stem cells have the power to heal and renew diseased organs. The same idea stands also as the basis for the work of the month of Elul: the call to return to the point from which we began to be formed, for that point also has the ongoing power to renew us.

- from Rabbi Peleh Ezrahi: Chagigah - The Inner Wisdom of the Hebraic Calendar

In fact, the letters that spell the word יוד Yud (Yud-Vav-Daled) can be rearranged to spell the word דיו dyo / ink. Yud is the drop of ink that starts every letter. These three letters are also a graphical display of expansion from a point to a line to an area. First there is a Yud, a nekudah / point. Then this point extends down into a kav / line. Then finally the dalet adds a horizontal vector and becomes a shetach / area.

- from Rabbi Dovber Pinson: Elul - Days of Transformation and Introspection

The virgin represents that part of us that has remained pure, untainted, and unchanged by the vicissitudes of life. It is this deep part within us, the pure holy soul, which calls for our attention this month.
- Melinda Ribner: Living in the Divine Flow - Elul

Yaakov represents the ‘revealed’ tzaddik [righteous person] or the path of perfection, and Eisav represents the potential Baal Teshuvah, the one who must struggle to return to wholeness along a more winding path full of mistakes and seeming detours..… Both of these paradigms are included within the Betulah, the pure soul-essence within us, which remains perfect no matter what.
- Rabbi Dovber Pinson: Elul - Days of Introspection & Transformation

Why is Elul connected to Virgo? The virgin symbolizes an original state of purity. Those born in Virgo tend towards precision and cleanliness. The shadow side of this can be self-righteousness, purism and irritability, but its light aspect indicates the tendency of this type to want to restore things to their higher state of perfection.
- Rabbi Peleh Ezrahi: Chagigah

Tammuz. Seeing. ראיה
Av. Hearing. שמיעה
Elul. Doing. עשייה

Tammuz corresponds to the sense of re’iya / seeing, and Av to shmi’a, hearing. These two Hebrew words begin with the letters reish and shin, which together spell the word רש rash / deprived or poor, as those two months are considered, at least on the surface, to be spiritually ‘deprived’ of goodness. Asiyah begins with the letter ayin, and when this letter is added to rest and shin, it spells the word שער sha’ar, gate. Elul is the sha’ar that closes the past year, and opens to the goodness of the year to come..…

When the Divine name Adonai is spelled out in full (spelling the names of the letters Aleph-Dalet-Nun-Yud, ie Aleph-lamed-phey, Dalet-lamed-tav, etc) there are 12 letters, corresponding to the 12 months of the year.

According to the count of months starting in Nisan, Tamuz and Av are the fourth and fifth months/letters in this sequence - Dalet and Lamed - and Elul is the sixth month/letter, Tav. The letters dalet-lamed spell דל Dal, another word for ‘poor,’ alluding to to the negative spiritual quality of Tamuz and Av. However, when we add the Tav of Elul, the word dal becomes the word דלת Delet, door. Again, Elul, is the door (or gate) that closes on the past year and opens to new possibilities for the coming year. The practices of Elul help us to specify, own, and achieve closure on the negativity of our past.
- Rabbi Dovber Pinson: Elul - Days of Introspection & Transformation

1 Elul New Year of Animals
On the 1st of Elul, we can imagine geese and hummingbirds flying unerringly thousands of miles. We can learn from the animal kingdom about the returning instinct.
- Rabbi Jill Hammer: The Jewish Book of Days

https://youtu.be/jbLmRVng6io
Lyrics, Rafael-Simkha Kahn; music, R’ Shlomo Carlebach

Return again, return again
Return to the land of your soul
Return to who you are
Return to what you are
Return to where you are
Born and reborn again