Ezra is the Book of Returnings. 70 years of captivity in Babylon have passed, and the Persian King Cyrus has decreed their return to rebuild the temple. This temple is a joy to the younger generations, but a sorrow to the elders who recall the glory of Solomon’s temple.
The Hebrew, Greek, and English titles for the Book are taken from the name of the Scribe-Priest who recorded the first two returns from Persia (and who led the second of those two returns).
Ezra the “son” (descendant) of Seraiah was a Zadokite priest & scribe of the Mosaic Law who was sent to Jerusalem under the warrant of the Persian King Artaxerxes. Ezra’s mission was to oversee the temple operations and guarantee the priesthood’s compliance with Mosaic Law. To this end, Ezra was entrusted with government funding—an astronomical expense account to fund whatever needs the priests & Levitesin Jerusalem might have.