# seven priests ... seven trumpets

"7 priests ... 7 trumpets" (See: [[rc://en/ta/man/jit/translate-numbers]])

# gave blasts on the trumpets

This means that they blew into their trumpets, causing them to make loud noises, multiple times. Alternate translation: "continually sounded the trumpets loudly" or "blew into the ram's horn trumpets continually"