The Tetragrammaton, or four-lettered Name of God, is here arranged as a tetractys within the inverted human heart. Beneath, the name Jehovah is shown transformed into Jehoshua by the interpolation of the radiant Hebrew letter סה, Shin.
The drawing as a whole represents the throne of God and His hierarchies within the heart of man.
In the first book of his Libri Apologetici, Jakob Böhme thus describes the meaning of the symbol: "For we men have one book in common which points to God. Each has it within himself, which is the priceless Name of God.
Its letters are the flames of His love, which He out of His heart in the priceless Name of Jesus has revealed in us. Read these letters in your hearts and spirits and you have books enough.
All the writings of the children of God direct you unto that one book, for therein lie all the treasures of wisdom. This book is Christ in you."
From Böhme's Libri Apologetici in the Secret Teachings of All Ages by Manly P. Hall