2 Jeshua son of Jozadak and his brother priests, along with Zerubbabel, the son of Shealtiel, and his relatives, went to work and built the Altar of the God of Israel to offer Whole-Burnt-Offerings on it as written in The Revelation of Moses the man of God.
Matthew Henry's Commentary on Ezra 3:2
Commentary on Ezra 3:1-7
(Read Ezra 3:1-7)
From the proceedings of the Jews on their arrival, let us learn to begin with God, and to do what we can in the worship of God, when we cannot do what we would. They could not at once have a temple, but they would not be without an altar. Fear of danger should stir us to our duty. Have we many enemies? Then it is good to have God our Friend, and to keep up communion with him. Our fears should drive us to our knees. The sacrifices for all these solemnities were a heavy expense for so poor a company; yet besides those expressly appointed, many brought free-will offerings to the Lord. And they made preparation for the building of the temple without delay: whatever God calls us to do, we may depend upon his providence to furnish us with the needful means.