 Complete the following phrase:  The Abraham Avinu Synagogue  was built by Hakham Malkiel Ashkenazi in the Jewish Quarter of Hebron in 1540. The domed structure represented the physical center of the Jewish Quarter of Hebron. Located in the Old City of Hebron, it became the spiritual hub of the Jewish community there and a major center for the study of Kabalah. It was restored in 1738 and enlarged in 1864. The synagogue stood empty since the 