A shofar is a musical horn made of a rams horn, used for Jewish religious purposes. It is blown during Rosh Hashanah services, every day except Shabbat during the preceding month of Elul, and at the end of Yom Kippur. The shofar is created by hollowing out a ram's horn, shaping it, and polishing it. The shofar lacks pitch-altering devices, with all pitch control done by varying the player's embouchure. The four sounds of the shofar are tekiah, shevarim, teruah, and tekiah gedolah, and they remind many people of a crying voice. The shofar is mentioned frequently in the Hebrew Bible, the Talmud, and rabbinic literature. The shofar is evocative of the Torah portion that is read on Rosh Hashanah, the story of the binding of Isaac, and it calls to mind the image of the ram stuck in the bush that Abraham ultimately sacrificed instead of his son. The shofar is also reminiscent of God's revelation at Sinai, which was accompanied by the sounding of a shofar, and it reminds us of our destiny to be a people of Torah, to pursue its study, and to practice its commandments. The shofar summons us to the feeling of humility before God's majesty and might, which are manifested by all things and by which our own lives are constantly surrounded.