Charles Ellicott Commentary 2 Chronicles 7:6

"And the priests stood, according to their offices; the Levites also with instruments of music of Jehovah, which David the king had made to give thanks unto Jehovah, (for his lovingkindness [endureth] for ever,) when David praised by their ministry: and the priests sounded trumpets before them; and all Israel stood." — 2 Chronicles 7:6 (ASV)

And the priests. —This verse is added by the chronicler, in his characteristic way of emphasizing the ritual, especially its choral and musical side (Compare to 2 Chronicles 5:11–13).

Waited on their offices. —Literally, And the priests upon their wards (watches) were standing, i.e., stood at their posts. Vulgate, “sacerdotes autem stabant in officiis suis.”

Instruments of music of the Lord —i.e., of sacred music, as we should say (Compare to 1 Chronicles 16:42).

Which David ... had made. —1 Chronicles 23:5.

To praise. —Give thanks to (Compare to 2 Chronicles 7:3 above).

When David praised by their ministry. —See margin; and 1 Chronicles 16:4–7. The Septuagint, ἐν ὕμνοις Δαυιδ διὰ τῆς χειρὸς αὐτῶν, takes b’hallçl substantively, as if it meant “in David’s psalmody,” perhaps with special reference to the great hallel of the synagogue. The Authorised Version gives the true meaning, namely, that the Levites were David’s ministers of praise.

Sounded trumpets. —Were trumpeting.

Stood. —Were standing.