Psalm 37:4 (NASB)
He will give you the desires of your heart.
A primitive reading of this verse would mean that God will grant all the desires of our hearts. The desires may be as simple as candy for a child to something more mature or complicated as a job or spouse. But a different read on the verse would mean not just our desires for ourselves but that God Himself will put in His desires and plans for us.
It is one thing to ask God to give us something, and it's an entirely different thing to find out what God's desires are and what He wants from us. Often, we see God as a benevolent Father who gives us all we desire, and He is that (Psalm 103:5). But He is also much more than that. God wants to put His plans, purposes, desires, and thoughts into our minds. He is looking for trusted saints to confide in (Psalm 25:14) who will be His coworkers (1 Corinthians 3:9). God desires saints willing to be used by Him for His glory and purposes. So, like Isaiah, let us say, "Here am I, O' God, send me!".