Zayin represents the spiritual force that drives the so called war of existence. Many words that start with Zayin represent a movement of some sort in general, and specifically one that allows the world to continue and survive.
For example: Zachar, man, who is needed in the perpetuation of creation. Zerah, seed, which allows a child to be born and plant life and vegetation to grow. Zikaron, memory, which connotes mental life and movement. Za’azuach, to tremble or shake. Zanav, tail, as on an animal. Zechila, drip or flow. Zan, to sustain.
Zayin looks like a seed, pointing towards the letter’s power of creative potential, movement and flow needed to sustain the world.
The first time that Zayin appears at the beginning of a word in the Torah is when Hashem is creating the world. The seeds were “mazreah zerah, to sprout forth.” The potential of the plant life and vegetation was hidden under the ground and was going to sprout forth at a later time.
Similarly, the Radvaz explains that the secret of Zayin was expressed when Hashem appeared to Moshe for the first time at the burning bush. Moshe asked for signs to show that he would be successful in his mission to redeem Am Yisrael from slavery. The passuk in Shemos 3:12 says, “v’Zeh l’cha ha’os, and this will be for you a sign,” referring to the Zayin.
The deeper understanding of this is that Hashem revealed to Moshe the power of the letter contained in the letter Zayin. Precisely through the force of movement needed for spiritual survival contained in the Zayin, you will win your war and Am Yisrael will be free.
The shape of the Zayin actually looks like a sword. The head looks like a handle, while its long leg resembles a blade. Zayin also resembles a hammer. The top of the letter is the like the head, while the leg is the handle. Zayin is like a weapon used to win wars to move the world forward towards the redemption process.
Kabbalistically, this is why the numerical value of Zayin is 7, corresponding to the seventh sefira of Netzach, endurance and eternity. Zayin represents the spiritual weapons of war to be minatze’ach, victorious over our enemies.
Rebbe Nachman explains that the main kli Zayin, weapon, of a Jew is his power of Tefilah. In reference to Yaakov, we read that he used bichrebi ubakashti, my sword and arrows. The world for arrows, bakashti, also means bakasha, request. Yaakov used his power of prayer to request all his needs from God! Our main battles can be fought through the world of Tefilah!
Zayin, 7, represents the spiritual world in contrast to the number 6. The world was created in 6 days. On the 7th day, Shabbos, Hashem rested, infusing the world with Divinity. 6 represents the total perfection of this world, like the 6 sides of a cube or the directions of north, west, east, south, up and down. The 7th day, Shabbos, is the Divine element which is necessary for the sustaining and movement of this world. It is therefore a mitzva to remember, Zachor, which starts with a Zayin, the Shabbos day.
As the crown on top of Zayin is called Zayanin, Zayin also means crown. Specifically on Shabbos, the 7th day, we crown Hashem as the King who is Zon, sustains, the world.
May we merit the 7th millennium represented by the Zayin, of which the navi Yeshaya said in perek 2:4, when Mashiach will come He will “judge between the nations, they will turn their swords into plowshares and spears into pruning hooks. Lo yisa goy el goy cherev v’lo yilmadu od milchama, nations will no longer lift sword towards each other and the art of war will no longer be practiced.
