From Martin Luther's Lectures on Isaiah:
He gives power to the faint.
-Isaiah 40:29a
...Reason willingly hears one thing--that God gives strength, but it does not want to be worn out and nothing. So all the self-righteous willingly receive strength from God, but they do not want to be faint...
But God gives strength to the weary, the oppressed, and the troubled. The emphasis lies on the word "faint," but we look for the stress on the word "power." It is as if God were saying: "You must be weary and emptied, so that there is no way out for you. Then I will give you strength. First you must become nothing, then consolation and strength will come."
Therefore let us learn to console ourselves when we are afflicted and say,
"What I do not have and what I cannot do, that Christ has and can do."
This, and other daily readings can be found in the compilation, Steadfast in Your Word: Daily Reflections from Martin Luther.