Then I brought up the leaders of Judah upon the wall, and appointed two great companies of them that gave thanks, of which one went on the right hand upon the wall toward the refuse gate:
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Bede
AD 735
The leaders of Judah (i.e., “confession” or “praise”) are all those more perfect teachers of the holy church who at the dedication of the city go up on top of the wall because when the time of retribution appears, they will be proven to have risen above the ordinary life of the holy church by their more exalted manner of living. For they are the ones concerning whom the Lord promises this holy church through the prophet, saying, “I have posted guardians on your walls.” Thus it is just that those today who have been placed in the office of watchman over the holy church’s walls will at that time also be distinguished by the glory of this same reward.
Choirs. This is not expressed in Hebrew and Septuagint, but must be understood. Protestants, "great companies of them that gave thanks. Whereof one went. "(Haydock)
The princes led the way, then the priests sounded the trumpets, (Numbers x. 8.) the Levites sung, and were followed by the people. All were divided into two equal parts, and went round half the city. (Calmet)
They set out from the dunghill-gate, on the west, and proceeded to the watch-gate, on the east, ver. 38. (Menochius)