Of the final three groups, the largest and most important is 
  
    
      
        
          
            
              
                T
                ¯
              
            
          
          
            9
          
        
      
    
    {\displaystyle {\bar {T}}_{9}}
  , that is associated with an important Kac–Moody Lie algebra 
  
    
      
        
          
            E
          
          
            10
          
        
      
    
    {\displaystyle \mathrm {E} _{10}}
  .The trisection of the angle was one of the three famous problems of antiquity.
Paul the Apostle went blind for three days after his conversion to Christianity. Judaism
Noah had three sons: Ham, Shem and Japheth
The Three Patriarchs: Abraham, Isaac and Jacob
The prophet Balaam beat his donkey three times. The prophet Jonah spent three days and nights in the belly of a large fish
Three divisions of the Written Torah: Torah (Five Books of Moses), Neviim (Prophets), Ketuvim (Writings)
Three divisions of the Jewish people: Kohen, Levite, Yisrael
Three daily prayers: Shacharit, Mincha, Maariv
Three Shabbat meals
Shabbat ends when three stars are visible in the night sky
Three Pilgrimage Festivals: Passover, Shavuot, Sukkot
Three matzos on the Passover Seder table
The Three Weeks, a period of mourning bridging the fast days of Seventeenth of Tammuz and Tisha BAv
Three cardinal sins for which a Jew must die rather than transgress: idolatry, murder, sexual immorality
Upsherin, a Jewish boys first haircut at age 3
A Beth din is composed of three members
Potential converts are traditionally turned away three times to test their sincerity
In the Jewish mystical tradition of the Kabbalah, it is believed that the soul consists of three parts, with the highest being neshamah ("breath"), the middle being ruach ("wind" or "spirit") and the lowest being nefesh ("repose"). Sometimes the two elements of Chayah ("life" or "animal") and Yechidah ("unit") are additionally mentioned. In the Kabbalah, the Tree of Life (Hebrew: Etz ha-Chayim, עץ החיים) refers to a latter 3-pillar diagrammatic representation of its central mystical symbol, known as the 10 Sephirot.