And he sent back from Babylon all the vessels which Cyrus had set apart; everything that Cyrus had ordered to be done, he also commanded to be done and to be sent to Jerusalem: This verse appears at first not to be part of the content of the letters of verse 48, but a resumption of the narrative. However, if the sacred objects Cyrus had ordered to be returned were in fact to be returned, Darius would have to order it. So it is appropriate to work this item into the list of things ordered by Darius in the letters mentioned in verse 48. Compare verse 44, where it is mentioned that Cyrus, when destroying Babylon, saved the holy objects of the Jewish Temple, with the intention of returning them.

Here is a model for verses 48-57:

• 48 The king also sent letters to the governors of the province of Phoenicia and Southwest Syria, and to those in Lebanon. Here are the instructions he gave in these letters:
The officials were to provide Zerubbabel with wood from the cedar forests in Lebanon, and help him rebuild Jerusalem. 49 No administrator, governor, or treasurer [or, No royal official] was to interfere with the freedom of the Jews traveling across his kingdom to Judah. No one had the authority to force their way into a Jewish home. 50 The Jews of Judah would not have to pay taxes. Idumeans [or, Edomites] who had been living in towns in Judah had to leave [those towns]. 51 Local officials were to provide 680 kilograms [1,500 pounds] of silver each year for the rebuilding of the Temple until it was finished. 52 In addition, the officials had to provide another 340 kilograms [750 pounds] of silver each year for the seventeen offerings that were required to be burned whole on the altar every day [or, that the Jews had to sacrifice on the altar each day]. 53 All the Jews who left Babylonia to rebuild the city of Jerusalem would be free persons, as would their descendants. This applied as well to all the priests making the journey. 54-55 Until the Temple was finished and Jerusalem fully rebuilt, the royal treasury had to provide for the priests and Levites, including the costs of the special garments they wore when performing their duties. 56 The men who guarded the city while the work was going on were to be paid [or, receive pay], and also be given [or, receive] some land. 57 All the sacred vessels that King Cyrus had set aside when he destroyed Babylon were to be returned to the land of Judah. Everything that Cyrus had ordered to be done concerning the return of the Jews was to be carried out.

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.