The better understanding of blessed which seems to carry more meaning in our culture is the word happy. Here in verse 6 Jesus is preaching and teaching that, happy are those who hunger and thirst for righteousness for they will be filled.
Immediately it becomes apparent that there is a double positive here. A verse with a blessing at both ends. Happiness and fullness are both being offered as the result of hungering and thirsting for righteousness.
The two verbs hunger and thirst are both the result of natural appetites. There could not be more familiar cravings. We all, on a daily basis, respond to our sense of hunger and thirst, we know where to go and what our bodies need in order to satisfy their demands. Yet the focus of these oh-so-familiar appetites is not food and drink but righteousness.
The question that must be answered is, “where do I find satisfaction in the search for righteousness?”