This psalm jumped out at me today as I what I lean on everyday.
"This is my comfort in my affliction - that your promise gives me life."
When things don't seem to be going the way we think they should - what do we lean on? our gifts, our abilities, hope that the world offers. This psalm is telling us to hope in the eternal word of the Lord - the everlasting covenantal promises of our God and King who gave us these very words.
This word comfort is only used twice in the whole Bible - it means comfort (go figure). But the other time is in Job - and we know what misery he faced. (If you want to read more about that, go to what Piper said about it here). It is good stuff. (Scroll down in the section to 1994 - there are 4 poems Piper wrote about Job.
Be comforted, not by your circumstances (even when they are good) - but by God's promises which bring you life.