What significant action does Ezra take during the second return in 458 BC?

During the second return to Jerusalem in 458 BC, Ezra's significant action in resolving mixed marriages reflects his commitment to restoring the covenant community and ensuring faithfulness to the Law of Moses. This was an important issue at the time, as the intermarriages between the Israelites and surrounding nations posed a threat to the religious integrity and identity of the Jewish people. Ezra's leadership in addressing this problem highlights his role as a religious reformer who sought to guide the people back to adherence to God's commands.

Ezra's efforts included not only addressing the issue of mixed marriages but also teaching the Law to the people, fostering a return to true worship, and reinstating the community's identity as God's chosen people. This aligns closely with the broader themes of restoration and reform that characterized the post-exilic period, emphasizing the importance of both spiritual and communal purity.

The other options reflect actions that, while significant in their own right, do not pertain specifically to Ezra's key contributions during this return. The rebuilding of the walls was primarily led by Nehemiah, prophecy about the Temple involves other leaders and prophetic voices, and copying the law, although reflective of Ezra's dedication, does not capture the breadth of his reformative actions regarding mixed marriages.