Spending wages, but unsatisfied?

All you who are thirsty,
come to the water!

You who have no money,
come, receive grain and eat;

Come, without paying
and without cost,
drink wine and milk!

Why spend your money for what is not bread;
your wages for what fails to satisfy?

Heed Me,
and you shall eat well,
you shall delight in rich fare.

Come to Me heedfully,
listen, that you may have life.

I will renew with you the everlasting covenant,
the benefits assured to David.

(Today's first reading - Isaiah 55:1-3)