"Worrying does not take away tomorrow’s grief; it takes away today’s strength."

". . . worrying is carrying tomorrow’s burden with today’s strength.  It’s carrying two days at once. . . .
     "I read somewhere, '. . . Worrying does not take away tomorrow’s grief; it takes away today’s strength.  It does not enable us to avoid evil, but it makes us incapable of dealing with it when it comes.'"

     Corrie Ten Boom, Reflections of God's glory:  newly discovered meditations by the author of The hiding place, [trans. Claire L. Rothrock] (Grand Rapids, MI:  Zondervan, 1999), 36-37.
     This is the closest I've come so far to the following, which I was asked to trace back to an actual source in Ten Boom herself.  Note that though very widely attributed to her without a citation of any kind, it is something that she claims here (at least) to have "read somewhere":

Worry does not empty tomorrow of its sorrow. It empties today of its strength.

     My thanks to Kendall Harmon, who was the one to notice that though I had supplied this as the source of the first two sentences (often associated with the third), I had missed the presence of the third later on (though I would stress again that she is quoting someone else here:  whom, she does not remember).
     The shift back and forth between "sorrow" and "grief" (not to mention "empty . . . of" and "take away") on the Internet could have something to do with how many times she repeated lines like these (her father's comments on worry as reported already in, I think, The hiding place, are justly famous), or they could be due to the varying choices of translators.  The copyright to the content of Reflections of God's glory is, after all, owned by Stichting Trans World Radio voor Nederland en België.  According to the prefatory material, TWR published a book of these (delivered from 1966) in Dutch in or before 1996, though Reflections of God's glory was based on a translation of the manuscripts.