The Volume of Sacred Law, or VSL for short, is what Freemasons call the religious text that is used in their ceremonies and traditionally placed onto their altar while the lodge is in session. In predominantly Christian areas such as the USA, it is most common to display the King James Bible. This is the same sacred text that candidates take their obligations upon.
If a lodge has members of different faiths it is often common to display multiple books upon the altar, to represent each member. The most common books of faiths besides the Christian bible are the Muslim Qur’an, the Hindu Bhagavad Gita, the Buddhist Discourses, the Jewish Tanakh, and the Sikh Granth Sahib. Generally Grand Lodges consider a text as permissible if it represents sacred teachings to the Mason. However, that is entirely jurisdictional.
One of the most notable individual VSL is the George Washington Inaugural Bible. It belongs to St. John’s Lodge No. 1 in New York City and has been used at its meetings since 1767. It is famous, however, for being the Bible used at the first inauguration of George Washington as President of the United States, and numerous presidents since then.