נָ֥חָה שָׁקְטָ֖ה כָּל־הָאָ֑רֶץ פָּצְח֖וּ רִנָּֽה׃
Вся земля в покое и тиха; они начинают петь.
Rashi
and opened their bones Heb. פִצֵּחוּ. They opened [them] to take out the marrow. Cf. (Isa.14:7) “They opened (פָצְחוּ) in song” -they opened their mouth in song.