Blowing the shofar was a well-known multi-purpose call in biblical times; One  identified ten ancient occasions when the shofar was used. It was used to announced the Creation, the Revelation at Mount Sinai, the exhortations of the prophets. It proclaimed a military advance; it called for a military retreat. It marked calendrical occasions such as the commencement of a new month. It announced the Word of God. One day it will be heard in the return of .
The shofar is commanded in the Torah (Numbers 29:1). It has two principal, seemingly contradictory, purposes — as a call to war (Numbers 10:1-10) and as a proclamation of freedom (Leviticus 25:9).