2Ch 2 Chronicles, chapter Second Book of Chronicles, chapter 7
And the Kohanim stood at their mishmerot (watches); the Levi'im also with kelei shir Hashem, (musical instruments of Hashem) which Dovid HaMelech had made to give thanks to Hashem — ki l'oham chasdo (for His mercy endureth forever) — whenever Dovid praised by their means; and the Kohanim sounded khatzotzrot (trumpets) opposite them, and kol Yisroel stood.1Ch 16:5; Num 10:10