In this verse, the psalmist tends to connect resting in the Lord and waiting patiently for Him. If this is true, and I believe it is, then to be able to wait patiently for the Lord, we must know what it means to rest in the Lord and how to do so. So what does it mean to rest in the Lord? The position of rest is the place where one casts all of his weight upon something else. For example, when we sit down on a chair, we cease to bear the upon our legs the weight of our bodies.
When we rest in the Lord, we transfer the burden of our lives upon Him. But we will only do this because we know and trust that He is able to bear the weight of the burden of our lives. So, in resting in the Lord, we cannot fail to introduce the factor of trust. And once we introduce the factor of trust, we are able to wait for God because we trust that He is capable of handling what we have committed to His care. Therefore, until we rest in the Lord, we cannot wait patiently for Him, because what it takes to do so is found only in resting in Him: trust.
Toni