"As Above, So Below" is the ancient precept of sacred geometry and Hermeticism. The ancients observed patterns in the heavens that were mimicked on Earth and they then incorporated these patterns into the building of their sacred structures, thus giving them a divine element of design. The number Seven was observed with what's now known as the 7 Classical planets: Moon, Mercury, Venus, Sun, Mars, Jupiter, and Saturn. Out of these 7 moving objects74 in the heavens74, 4 don't cast shadows74 on Earth (Venus does), 4 can't easily be seen during the day (Venus can be).
Tracking the Moon's cycle (and the 7 Classical planets) was perhaps the origin of mathematics and numerology, astronomy and astrology. The pattern of the lunar phases displayed 4 phases of roughly 7 days (~7.4 days) each, thus establishing the 7-day week and 4 weeks in a 'moonth'/month. Besides the New Moon, there are 28 days of moonlight every lunar month/cycle. The woman's menstrual cycle was observed as being an average 28 days. And when using eight phases of the Moon, 7 are lit and the second quarter Half Moon is mirrored 4 phases later in the last quarter Half Moon. The lunar year was observed as being roughly 11 days - 7 day week + 4 days - short of the solar year.
The ancient Sumerians and Egyptians observed Orion as the primary asterism with its 7 stars: 4 making up his shoulders and feet with the remaining three making up Orion's Belt. The Big Dipper is 7 stars with 4 in its quadrilateral bowl. It points towards Polaris which is the tip of the handle of the Little Dipper: again 7 stars with 4 in its bowl. Mars was observed to have a 47-year cycle against the background of stars in relationship to Earth and Sun.
Thus, the Egyptians took the regular cubit of 6 palms x 4 fingers = 24 digits (see graph of Vitruvian Man) and added a palm to create the sacred royal cubit of 7 palms x 4 fingers = 28 digits. Royal cubits were used in the design of all sacred buildings in Egypt including Imhotep the architect of the first pyramid - the Step Pyramid of Djoser. The Great Pyramid of Giza was designed to be 280 royal cubits high.
Bereshit 1:1 / Genasis 1:1 בְּרֵאשִׁית, בָּרָא אֱלֹהִים, אֵת הַשָּׁמַיִם, וְאֵת הָאָרֶץ This is the original Hebrew of the first verse of the Torah/Bible; it's 7 words and 28 (7x4) letters. Of course, it translates to, "In the beginnin74g, GOD7_4 created the heavens74 and the earth."