Ezra - Chapter 3

It says in Hebrews 9:

"In fact, the law requires that nearly everything be cleansed with blood, and without the shedding of blood there is no forgiveness."

The law is looking ahead to the shedding of Jesus blood on the cross - the ultimate source of forgiveness.

In Ezra 3 we see the people returning from exile, and their plans to rebuild the temple.  Their first act, before working on the temple building, was to rebuild the altar.

"Then Joshua son of Jozadak and his fellow priests and Zerubbabel son of Shealtiel and his associates began to build the altar of the God of Israel to sacrifice burnt offerings on it, in accordance with what is written in the Law of Moses the man of God. Despite their fear of the peoples around them, they built the altar on its foundation and sacrificed burnt offerings on it to the Lord, both the morning and evening sacrifices. Then in accordance with what is written, they celebrated the Festival of Tabernacles with the required number of burnt offerings prescribed for each day. After that, they presented the regular burnt offerings, the New Moon sacrifices and the sacrifices for all the appointed sacred festivals of the Lord, as well as those brought as freewill offerings to the Lord. On the first day of the seventh month they began to offer burnt offerings to the Lord, though the foundation of the Lord’s temple had not yet been laid."

These sacrifices are symbols of Jesus' sacrifice, and are central to the restoration of the people in the God's promised land.