Well, this morning when I first read this verse, I was coming it at it from a slightly different point - but having looked deeper into the words the psalmist chose to use - I get a new meaning:
"I entreat your favor with all my heart, be gracious to me according to your promise."
We must beg, be sick in front of, be weak, be humble - in front of God. We are nothing and are dead in our trespasses and sins before a holy God. Only the humble and contrite in heart will He accept and allow to worship Him - he will reject the proud. The word Favor here also means - FACE. We should be humble to come before - always seeking - the face of God (not the gifts of God), but literally the very face of God.
With all of my heart. Piper introduced me to this verse: Ps 86.11 - Unite my heart to fear your name. Same thing - with everything I am I want to come before the Lord and seek His face. The whole of my everything - in this definition or explanation there is no room for dissection or parts of us. There is no compartmentalization - forbid it - say bye to it. It doesn't belong in the Christian life.
Be gracious - show pity to the sick - again, referring to his position before the Lord - his sickness and weakness - he asks for Him to be gracious to Him according to the promise, very word, of God - who is able and willing to keep all of his promises.
Aren't you glad?