And they completed it by the command of the Lord God of Israel: This clause simply states that the people had obeyed the Lord’s command by completing the construction of the Temple. For the Lord God of Israel, see 1 Esd 1.48. This clause may be rendered “So they completed building the Temple as the Lord God of Israel had commanded.”

So with the consent of Cyrus and Darius and Artaxerxes, kings of the Persians, the holy house was finished by the twenty-third day of the month of Adar, in the sixth year of King Darius: This additional statement gives three Persian emperors due credit for their sponsorship and support of the building project, and gives the date when the work was finally done. Artaxerxes (presumably Artaxerxes I) is out of place here, since he did not begin his rule until 465 B.C., fifty years after the completion of the Temple (see the introductory comments on 1 Esd 2.16-30). Adar was the twelfth month of the Hebrew calendar, running from about mid-February to mid-March in the modern Western calendar; the twenty-third day of the month was in early March. The sixth year of King Darius was 515 B.C.

We suggest rearranging the material in verses 4-5 by combining them as follows:

• The holy Temple was completed [or, They finished building God’s Temple] on the twenty-third day of the month Adar, in the sixth year of King Darius’ reign [or, in the sixth year that King Darius ruled Persia].* Three Persian kings had supported the work: Cyrus, Darius, and Artaxerxes. The people had obeyed the command of the Lord God of Israel by completing it.
* This would be during early March of 515 B.C.

Quoted with permission from Bullard, Roger A. and Hatton, Howard A. A Handbook on 1-2 Esdras. (UBS Helps for Translators). Miami: UBS, 2019. For this and other handbooks for translators see here.