They say each word as they push or pull. The song goes as follows:
Keo cua lua xe (Keo cua means “to ‘pull’ a saw”; lua xe means “to adjust the saw to the wood grain)
Ong tho nao khoe (The worker who is strong)
Ve an com vua (Returns to eat the king’s rice)
Ong tho nao thua (The worker who cannot catch up)
Ve bu ti me (Returns to suck his mother’s milk)

Or, an alternate version:
Keo cua lua xe
Lam it an nhieu (Work a little, eat a lot)
Nam dau ngu day (Sleep wherever we lie down)
No lay mat cua (They steal the saw)
Lay gi ma keo (How will we saw?)