VI. The blessedness of desiring righteousness
After this the Lord goes on to say: “blessed are they who hunger and thirst after righteousness, for they shall be satisfied.” It is nothing bodily, nothing earthly, that this hunger, this thirst seeks for: but it desires to be satiated with the good food of righteousness, and wants to be admitted to all the deepest mysteries, and be filled with the Lord Himself. Happy the mind that craves this food and is eager for such drink: which it certainly would not seek for if it had never tasted of its sweetness.
But hearing the Prophet's spirit saying to him: “taste and see that the Lord is sweet;” it has received some portion of sweetness from on high, and blazed out into love of the purest pleasure, so that spurning all things temporal, it is seized with the utmost eagerness for eating and drinking righteousness, and grasps the truth of that first commandment which says: “You shall love the Lord your God out of all your heart, and out of all your mind, and out of all your strength:” since to love God is nothing else but to love righteousness. In fine, as in that passage the care for one's neighbour is joined to the love of God, so, too, here the virtue of mercy is linked to the desire for righteousness, and it is said:
Source: Sermons (New Advent)