Sefer HaZohar
'The Book of Splendour'
Rabbi Shimon bar Yochai went and fled to the wilderness of Lud, and hid in a cave, along with his son Rabbi Elazar. A miracle happened: a carob tree and a well were produced for them. They ate from the carob and drank the water. Elijah [the prophet], may his memory be a blessing, would visit them twice each day and teach them. And no one knew about them.
(based on Talmud, Shabbat 33b).
Rabbi Abba, who was sitting before Rabbi Shimon [bar Yochai], said to him: Look here, I have asked many times about the meaning of the shofar, but so far I have not had a satisfying answer.
He [Rabbi Shimon] replied: This is the true explanation. Why does Israel require the ram's horn (shofar) on this day, but not another type of horn (qeren)? For it is known where the other type of horn comes from, and we do not wish to adhere to judgment (din). However we have learned that in word and deed we should perceive and deal with secret things.
Come and see! When the supernal shofar, in which all lights are included, departs and does not illumine its children, then judgment is awakened, and thrones are set up for a court (bei dina). And this shofar is called 'Isaac's ram', i.e. Isaac's power [99a/99b], the praise of the 'fathers'. When that great shofar departs, and does not suckle its children, then Isaac is strengthened and prepares himself for judgment in the world.
When that shofar is awakened, and when people repent of their sins, they should draw the sound of the shofar from below, and that sound ascends, and there awakens another, supernal shofar, so that mercy (rachamei) is awakened and judgment departs. We must perform a physical act with the shofar, in order to awaken the other shofar, and to produce those sounds with that shofar below that will produce all those sounds from above which are included in that supernal shofar, so that it be awakened to go out.
And with those sounds from below Israel is given strength above, and therefore we must blow the shofar at its proper time, on this day, and with the sounds in their proper series, intending by this to arouse the other shofar above, which contains all the sounds.
The first series: the [first] sound [=tekiah] is produced, is adorned above, rises through the firmaments, and breaks through the lofty mountains, until it reaches Abraham, on whose head it comes to rest. He is adorned and awakened and prepares the throne. In a book of aggadah, we are taught that at the moment that the first sound ascends, Abraham is awakened and adorned, and prepares the throne, and Father [and Mother] command it.
Meanwhile, the second sound [=shevarim-teruah] is produced, strong enough to break the powers of wrath--for this second series of sounds breaks these powers. When it goes forth, all the judgmental powers that have been awakened against it are broken, until it comes to Isaac's place. When Isaac is awakened, and sees Abraham preparing the throne to stand before him, then he is humbled and breaks the harsh power. And the one who blows the shofar should concentrate his heart and mind on this, in order to break the power and strength of harsh judgment, as it is said: 'Happy the people who know the shofar's blast' (Psalm 89:16), i.e. that know its 'breaking-[power]' [cf. Psalm 2:9, where tera'em means 'you shall break them'].
The third series [=tekiah]: the sound is produced, arises, breaks through all those firmaments, awakens mercy, until it reaches the head of Jacob. [99b/100a] Then Jacob is awakened and sees Abraham preparing himself on the other side. The two of them then seize Isaac, one on each side, so that his power cannot escape. These three sounds all form one series.
Just as they [the six middle sefirot] are united above as 'One,' so too is she [the sefirah of Malchut = the Shechinah] united below in the mystery of 'One,' so that she might correspond to them. The Holy One, Blessed be He, [=the sefirah of Tif'eret] who is one above, does not sit on His throne of glory, until she has entered into the mystery of 'One,' as He has, to become one in one. And this, we have taught, is the secret meaning of (the verse:) the Lord [Tif'eret] is one and His name [Malchut] one' (Zechariah 14:9). [135a/135b]
It is also the secret meaning of Shabbat [Malchut], which is united in the mystery of 'One,' that He [Tif'eret] might dwell with her in the mystery of 'One.' (It is also the meaning of) the prayer for Shabbat evening, for then the holy throne of glory [Malchut] is united in the mystery of 'One,' and prepared for the Supernal King [Tif'eret] to sit upon.
When Shabbat comes in, she is totally separated from the 'Other Side' and all the forces of judgment are severed from her. She is left free to be united with the holy light, and is adorned with many crowns by the Holy King. All the authorities of anger and the lords of judgment flee, so there is no other authority (apart from her).
Then her face shines with light from on high, while she is crowned by the holy people below, all of whom are adorned with new souls. Then the service of prayer (comes, that they may) bless her joyfully, with shining faces, and say: Barechu ('Bless...!')