“Let them praise his name in choir” (Ps 149:3). What does “choir” mean? Many people know about choirs, and since we are speaking in a city, almost everyone knows. A choir is a harmony of singers. If we sing in a choir, we sing in harmony. If in a choir of singers someone sings discordantly, he offends our ears and disturbs the choir. A voice out of tune disrupts the harmony of the singers, and a dissonant heresy disrupts the harmony of those praising God. The choir of Christ is now the whole world. Christ’s choir resounds from east to west. Consider whether Christ’s choir extends so far. Another Psalm says: “From the rising of the sun to its setting praise the name of the Lord” (Ps 112[113]: 3). “Let them praise his name in choir” (EnPs 149, 7; PL 37, 1953).