This makes it very clear that although we should always ask God for the desires of our heart, we should be mindful of out true motives, as God knows our hearts and will only grant our requests if they are selfless or are right to be asked for at the time, if we ask Him for money but only so we can live an extravagant lifestyle, we cannot blame God for not giving what we ask for, however if we ask for wealth and our desire is right in our hearts and God's eyes then He will grant it in His time.