In the Lord’s hand the king’s heart is a stream of water
    that he channels toward all who please him.

A person may think their own ways are right,
    but the Lord weighs the heart.

Proverbs 21:1-2

To begin chapter 21, we have four verses that deal with the king’s relationship with God. These first two concern the king’s heart. In verse 1, there is an allusion to the ancient method of watering a field. A water source flows into several channels that go to different parts of the field in the ancient near East. These channels were closed off until needed, and then the water could be made to flow to the area the farmer intended. This allusion illustrates God’s ability to channel a ruler’s favor to one or more people who deserve it, should God see fit to intervene.

The second verse reminds us that when a person, for example, a king, does something, they expect their ways to be the right way in the situation at hand.  Yet, God is the One who decides and weighs their heart to determine their motivation, and He will judge accordingly.

To do what is right and just
    is more acceptable to the Lord than sacrifice.

Haughty eyes and a proud heart—
    the unplowed field of the wicked—produce sin.

Proverbs 21:3-4

The king, and come to think of it, all of us as well should strive to do our very best to deal with other people fairly and properly, as Jesus would do. God expects this, and it is far more important to Him than it is for us to follow any ritual or form of worship, for to do what is right and to trust in God is what He most wants from His people.

The last of these verses, verse 4 is dealing with pride, something a king or important leader is more susceptible to than most. Clearly, there is a warning here: Getting carried away with pride and conceit is the beginning of a slide into out and out wickedness, and when that takes hold of a person’s life, the ending is always a bad one.