Ps 106:13-15 The children of Isreal complained and murmured about eating just manna, they cried about wanting to eat meat, God sent so much meat that they ate until there were sick, Vs 15 kjv put it as "..And he gave them their request but sent leanness to their soul" We can force God hands to do things for us or give us things he doesn't want to give us either because it's not in his will or not his timing, when this happen, we may actually get them but we realise the satisfaction we thought we would have won't be there. ..that's a leanness in the soul, I am learning to Trust God so much to know that as a loving Father he will not withhold any good thing from me, so if I am not getting an answer ,I dnt go forcing things, I trust God's timing. Also it's very important to know God's mind on issues, that way you won't pray needless prayers ,that way only God's perfect will comes to pass in our lives and not his permissive will.