There are two level's of meaning to this particular proverb. They are both a blessing to those who read it, understand it, and who look to the Lord for their subsistence.
Jehovah will not allow the soul of the righteous to hunger. That is what this passage says. It refers on the surface level to the simple fact that God is going to provide basics for believers. David said, "I was young, and now I am old, yet I have never seen the righteous forsaken or their children begging bread." What a comfort to us this should be. God promises to make provision for us. Often our problem is that we want way more than provision. God promises food and raiment (clothing) and with these we should be content. Yet in our culture we have come to call too many things "necessities." In fact there are entire theological systems based upon us getting whatever we claim from God - no matter how blatent the greed becomes. Hopefully we see through the ruse of selfish and fleshly greed and rejoice when we are able to eat and clothe ourselves each day. But there is more to this proverb - a deeper level. God will not allow the SOUL of the righteous to hunger. If we desire the Lord - if we hunger for God - our soul will be satisfied! Blessed are the hungry, for they shall be filled! Blessed are those who hunger and thirst for righteousness, for they shall be filled! God promises to us a fullness that can never be defined by food and drink alone. It is the fullness of the Spirit. It is a fullness that describes how God Himself comes to fill us to the deepest levels of our hearts and souls with Himself. This, even more than just a promise of food, should fill our hearts with joy unspeakable, and full of glory!
There is a comparison here though. We read that the craving of the wicked will be thrust away. The craving of the wicked is the desires and lusts that they have without limits and without bounds. The wicked will always seek to push the limits of what is allowed. They will always seek to push the laws of the land to where they can pursue greater and greater godlessness. Because it is the desire of the wicked - these desires and wants are ungodly ones - desires that are clearly outside of the scope of God's will and desires. The Lord promises to thrust away these things. When I read this I think of that horrific final day when God's judgments on all things, all choices, all lifestyles is made clear. In that all important day those who lived for wickedness will hear those eternally aweful words, depart from me, you wicked, into everlasting fire - I never knew you! In that moment every desire of the wicked - every lifestyle that is outside God's purposes will be thrust away.
There is one thing though that I think we need to grasp to see this proverb clearly. We usually see words like "wicked" and think of only the most heinous of sinners. The wicked are those outside of God's grace and salvation in Christ. The "wicked" might look to us like the model citizen, the good ole boy, the nice girl, the sweet couple. Yet, if they reject their sinfulness in God's sight and the only remedy which is Jesus Christ crucified and resurrected from the dead - they are indeed wicked. Even their 'nice' lifestyles and 'decent-looking' lives will be thrust away. When our desires run contrary to those of the Lord - we place ourselves firmly in the place and the choices of the wicked. Their lives may look full and meaningful from the outside - but inwardly they are empty. Their desires will be thrust away. Yet the righteous - their soul will be satisfied as with fatness. They have Christ Jesus as an everlasting portion. Their hungers and desires in Him will be fulfilled!