From the early Church Fathers to now.
1 Jewish · 1 Methodist · 1 Catholic · 1 Reformed
“For the king’s commandment was concerning them, and an order among the singing men day by day.”
“For the command of the king was upon them and [his] trust The king trusted them. upon the singers to spend money from King Darius’s treasury. for the daily requirements in order to perform the requirements of the Temple.”
“It was the king's commandment - By the king some understand David, and others Artaxerxes. It is most probable that it was the latter; who wished that a provision should be made for these, a part of whose office was to offer up prayers also, as well as praises. For we know that Darius made an ample provision for the priests, that they might offer sacrifices of sweet savor unto the God of heaven; and pray for the life of the king and of his sons, Ezr 6:10. Some have thought that they had been Jewish singers employed in the service of the Persian king, to whom he had given a salary, and to whom he wished still to continue the same.”
“King’s. David’s, (chap. xii. 24,) or perhaps the Persian monarch, who had appointed a maintenance for the priests, &c., 1 Esdras vi., and vii. (Calmet) — Order. Hebrew, “that a certain portion should be for the singers, due for every day.” (Protestants)”
“it was the king's commandment--It was the will of the Persian monarch in issuing his edict that the temple service should be revived in all its religious fulness and solemnity. As this special provision for the singers is said to have been by the king's commandment, the order was probably given at the request or suggestion of Ezra or Nehemiah.”
The in-app commentary runs from the Fathers to the early-modern record, then stops — that's where the public-domain sources end, not where the reading does. For the modern reading, follow the sources directly.