25 The Hebrew text has שַׁחְרָהּ (shakhrah), which is either a suffixed noun (“its dawning,” i.e., origin) or infinitive (“to look early for it”). Some have suggested an emendation to שַׁחֲדָהּ (shakhadah), a suffixed infinitive from שָׁחַד (shakhad, “[how] to buy it off”; see 1005 שָׁחַד). This forms a nice parallel with the following couplet. The above translation is based on a different etymology of the verb in question. III שׁחר references a verbal root with these letters (שׁחד) that refers to magical activity.
26 Heb “you will not know”; “you cannot foresee.”

In other versions

But evil shall come upon you,

which you will not know how to charm away;

disaster shall fall upon you,

for which you will not be able to atone;

and ruin shall come upon you suddenly,

of which you know nothing.

Disaster will come upon you,

and you will not know how to conjure it away.

A calamity will fall upon you

that you cannot ward off with a ransom;

a catastrophe you cannot foresee

will suddenly come upon you.

But disaster will happen to you;

you will not know how to avert it.

And it will fall on you,

but you will be unable to ward it off.

Devastation will happen to you suddenly

and unexpectedly.

So disaster will overtake you,

and you won’t be able to charm it away.

Calamity will fall upon you,

and you won’t be able to buy your way out.

A catastrophe will strike you suddenly,

one for which you are not prepared.

And evil shall come upon you, you will not know;

it will be on the lookout for her.

And disaster shall fall upon you; you will not be able to avert it.

And ruin shall come on you suddenly; you do not know.

Therefore shall evil come upon thee; thou shalt not know from whence it riseth:

And mischief shall fall upon thee; thou shalt not be able to put it off:

And desolation shall come upon thee suddenly, which thou shalt not know.

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