The numbers 3, 5, and 7 are prominent in speculative Masonry, as shown in _Isis Unveiled_. A Mason writes:

There are the 3, 5, and 7 steps to show a circular walk. The three faces of 3, 3; 5, 3; and 7, 3; etc., etc. Sometimes it comes in this form: 753/2 = 376.5, and 7535/2 = 3817.5, and the ratio of 20612/6561 feet for cubit measure gives the Great Pyramid measures.

The Secret Doctrine, Vol. 1 of 4 — Part 109

Three, five and seven are mystical numbers, and the last and the first are as greatly honoured by Masons as by Parsis—the Triangle being a symbol of Deity everywhere.(202) As a matter of course, Doctors of Divinity—Cassel, for instance—show the _Zohar_ explaining and supporting the Christian Trinity(!). It is the latter, however, that had its origin from the [triangle], in the archaic Occultism and Symbology of the Heathen. The Three Strides relate metaphysically to the descent of Spirit into Matter, of the Logos falling as a ray into the spirit, then into the soul, and finally into the human physical form of man, in which it becomes Life.

The Secret Doctrine, Vol. 1 of 4 — Part 109

The Kabalistic idea is identical with the Esotericism of the archaic period. This Esotericism is the common property of all, and belongs neither to the Âryan Fifth Race, nor to any of its numerous sub‐races. It cannot be claimed by the Turanians, so‐called, the Egyptians, Chinese, Chaldeans, or by any of the seven divisions of the Fifth Root Race, but really belongs to the Third and Fourth Root Races, whose descendants we find in the Seed of the Fifth, the earliest Âryans. The Circle was with every nation the symbol of the Unknown—“Boundless Space,” the abstract garb of an ever present abstraction—the Incognizable Deity. It represents limitless Time in Eternity. The Zeroâna Akerne is also the “Boundless Circle of Unknown Time,” from which Circle issues the radiant Light—the Universal Sun, or Ormazd(203)—and the latter is identical with Cronus, in his Æolian form, that of a Circle. For the Circle is Sar and Saros, or Cycle. It was the Babylonian God whose circular horizon was the visible symbol of the invisible, while the Sun was the One Circle from which proceeded the cosmic orbs, of which he was considered the leader. Zeroâna, is the Chakra, or Circle, of Vishnu, the mysterious emblem which is, according to the definition of a Mystic, “a curve of such a nature that as to any, the least possible, part thereof, if the curve be protracted either way, it will proceed and finally reënter upon itself, and form one and the same curve—or that which we call the circle.” No better definition could thus be given of the natural symbol and the evident nature of Deity, which having its circumference everywhere (the boundless) has, therefore, its central point also everywhere; in other words, is in every point of the Universe. The invisible Deity is thus also the Dhyân Chohans, or the Rishis, the primitive seven, and the nine, without, and ten, including, their synthetical unit, from which IT steps into Man.

The Secret Doctrine, Vol. 1 of 4 — Part 109