What is the significance of "Ki Mitzvas ha'Melech Aleihem"?
Rashi: The king trusted them.
Malbim #1: The king commanded that they be appointed constantly. This was from the days of David, like it says in Divrei ha'Yamim I, 9:22-23.
Malbim #2: Since they merited this from the days of David, also Melech Paras commanded that they be appointed on this.
Why does it say "va'Amanah Al ha'Meshorerim"?
Rashi: They would take money from the storehouse of Daryavesh ha'Melech.
Ibn Ezra: Amanah is what lasts and has clout, like "Anachnu Koresim Amanah" (10:1).
Malbim: He was also the expert singer. Amanah is like Uman (professional). He taught and appointed over the singers.
What do we learn from "Devar Yom b'Yomo"?
Rashi: In order to do needs of the Bayis.
Malbim: He decided which Mizmor to sing each day, and which tune for it.
