Sefer Yetzirah means “Book of Formation” in Hebrew. The origin of the text is unknown. Sefer Yetzirah is the earliest text of Kabbalah. For translation, commentary and detailed information about the history of Sefer Yetzirah, Aryeh Kaplan’s book  is recommended.
The Sefer Yetzirah exists in multiple versions: 1) The Short Version, 2) The Long Version, 3) The Saadian Version 4) Gra Version. The Short Version comprises about 1300 words while the Long Version has less than 2500 words. In all versions there are 6 chapters. In the 13th century CE, Abraham ben Samuel Abulafia noted the existence of both the short and long versions.
In many of the Kabbalistic commentaries, verse 1:1 is translated as:
“…He engraved Yah…, the Living God,.. and He created His Universe with three books (Sepharim), with text (Sepher), with number (Sephar), and with communication (Sippur).” 
According to Aryeh Kaplan the “He” refers to the Infinite Being (Ein Sof) who is above all divine Names. Ein Sof of Kabbalah corresponds to the Nirguna Brahma of Tantra Yoga. Ein Sof (Nirguna Brahma) is the Absolute Being or Godhead.
Saadia Gaon translates Yah as “the Eternal”. The Yah of Kabbalah corresponds to the Saguna Brahma of Tantra Yoga. The Yah (Saguna Brahma) is the manifest divinity. The Yah also corresponds to Haqq (Reality) used in Sufi literature.
Sefer Yetzirah calls Yah the “Living God.” This is very similar to my description of Reality (Yah, Haqq, Saguna Brahma) as the “infinite life” or the “eternal life.” Infinite potential of the Godhead (Ein Sof) is transformed into infinite life (Yah).
The “engraving” concept of Sefer Yetzirah is very similar to Rumi’s “manifestation through opposites” concept
“Hidden things are manifested by their opposites, but
as God has no opposite He remains hidden. God’s light
has no opposite in the range of creation whereby it
may be manifested to view.” – Rumi
When you engrave letters on a plate you are creating an “opposite space”. The “opposite space” sounds very similar to “Hidden things are manifested by their opposites.”
 Aryeh Kaplan, “Sefer Yetzirah The Book of Creation”, Weisner (1997), ISBN-13: 978-0-87728-855-8