They are vanity
hebel (heh'bel)
emptiness or vanity; figuratively, something transitory and unsatisfactory; often used as an adverb -- altogether, vain, vanity.
the work
ma`aseh (mah-as-eh')
an action (good or bad); generally, a transaction; abstractly, activity; by implication, a product (specifically, a poem) or (generally) property
of errors
ta`tua` (tah-too'-ah)
a fraud -- error.
in the time
`eth (ayth)
time, especially (adverb with preposition) now, when, etc.
of their visitation
pquddah (pek-ood-daw')
visitation (in many senses, chiefly official) -- account, (that have the) charge, custody, that which...laid up, numbers, office(-r), ordering, oversight, + prison, reckoning, visitation.
they shall perish
'abad (aw-bad')
to wander away, i.e. lose oneself; by implication to perish (causative, destroy)
