The following paragraph is from Dr. Asher Eder’s book The Star of David, which was published in 1987 in English in Jerusalem by Rubin Mass Ltd. The publication here is courtesy of Oren Mass
The number three plays an important role in almost every nation and culture, and in various disciplines, appearing as a symbolic, sacred or mystical number. It can depict the father-mother-child relationship in any real or allegorical context. In Hindu philosophy, the prime power Brahm adopts three aspects: Brahma, Vishnu, and Shiva (Creator, Sustainer and Purifier). The Chinese I Ching refers to hexagrams, each one composed of two trigrams.
Our own creative processes can be depicted by an equilateral triangle. The three decisive properties involved could then be discerned as
a) the will to create;
b) the energies or forces which supply the means to create;
c) the giving of direction, order, and form to these forces so they do not remain in a state of chaos.
The number three has significance also in the Tanakh, where its appearance is usually linked to new developments. Among the obvious examples are the three types of light spoken of in Genesis, i.e. the Divine Light (אור , verse 3) and the two great lights מארת, (me'orot; verses 14-17) which are to rule day and night, respectively. Noah's Ark has three levels, and Noah's three sons Shem, Ham and Japhet are not only the physical ancestors of the nations after the Flood but, as their names imply, archetypal representatives of spirit, feeling and intellect - the three aspects of human nature.10 Abraham's three main descendants, Ishmael, Israel, and Esau gave to the Hamites, the Semites and the Japhetites their respective religio-cultural bearings, corresponding to the three lights (notwithstanding occasional mutual intrusions like Moslem Persia or Christian countries in Africa).