[שׂ], Shin [שׁ].

The 21st letter in the Hebrew alphabet. This letter was used to represent two sounds, and in later periods, these were distinguished by the use of a diacritical mark. A dot placed over the left-hand “horn” [שׂ] gave the pronunciation “s,” while a dot placed over the right-hand “horn” [שׁ] gave the pronunciation “sh.”

In the Hebrew, each of the eight verses of Psalm 119:161-168 begins with this letter.