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.
3 (three) is a number, numeral and digit. It is the natural number following 2 and preceding 4, and is the smallest odd prime number and the only prime preceding a square number. It has religious or cultural significance in many societies. Evolution of the Arabic digit
The use of three lines to denote the number 3 occurred in many writing systems, including some (like Roman and Chinese numerals) that are still in use. That was also the original representation of 3 in the Brahmic (Indian) numerical notation, its earliest forms aligned vertically. However, during the Gupta Empire the sign was modified by the addition of a curve on each line. The Nāgarī script rotated the lines clockwise, so they appeared horizontally, and ended each line with a short downward stroke on the right. In cursive script, the three strokes were eventually connected to form a glyph resembling a ⟨3⟩ with an additional stroke at the bottom: ३. The Indian digits spread to the Caliphate in the 9th century. The bottom stroke was dropped around the 10th century in the western parts of the Caliphate, such as the Maghreb and Al-Andalus, when a distinct variant ("Western Arabic") of the digit symbols developed, including modern Western 3. In contrast, the Eastern Arabs retained and enlarged that stroke, rotating the digit once more to yield the modern ("Eastern") Arabic digit "٣".In most modern Western typefaces, the digit 3, like the other decimal digits, has the height of a capital letter, and sits on the baseline.