This has been the last central text for this series of messages. There's a frame of mind- a kind of heart, that God is particularly likely to work with and bless. The text says He gives this kind of person His special attention and notice. It's not that He loves this person and not others. Rather, it's that He sees the fertility - the potential - for His unfolding plan in this heart.
In the last message we looked at two passages that describe something similar to a trembling heart, but which are not quite the same. In Acts 24:24-25 we studied the response of Felix to Paul's words of witness. The text, in some translations, actually says Felix "trembled" at what Paul said. But it was not the trembling described by our text from the Prophet Isaiah.
Then we studied the words of the apostle James in James 2:19. Here James describes the kind of trembling that takes place in demons at the truth of God's Word. They know the truth. They believe the truth. And it makes them tremble. But neither of these passages deals with the kind of heart God values or esteems.
Doesn't God hear everyone who calls out to Him? That's the issue of this text.