In the beatitudes Christ blesses the unexpected and as he approaches the idea of righteousness his language slightly shifts. He speaks of those who desire righteousness in terms of the most basic and primal human needs- hunger and thirst. There are those who literally and figuratively hunger and thirst for righteousness in their lives and the lives of others. Often they are treated with disdain as not being willing to accept the "real world". Christ comes and says they are blessed but not only are they blessed they will be filled, their need will be met, their hunger will be satisfied.