John Gill

Blessed are they which do hunger and thirst,.... Not after the riches, honours, and pleasures of this world, but after righteousness; by which is meant, not justice and equity, as persons oppressed and injured; nor a moral, legal righteousness, which the generality of the Jewish nation were eagerly pursuing; but the justifying righteousness of Christ, which is imputed by God the Father, and received by faith. To "hunger and thirst" after this, supposes a want of righteousness, which is the case of all men; a sense of want of it, which is only perceived by persons spiritually enlightened; a discovery of the righteousness of Christ to them, which is made in the Gospel, and by the Spirit of God; a value for it, and a preference of it to all other righteousness; and an earnest desire after it, to be possessed of it, and found in it; and that nothing can be more grateful than that, because of its perfection, purity, suitableness, and use: happy souls are these, for they shall be filled: with that righteousness, and with all other good things, in consequence of it; and particularly with joy and peace, which are the certain effects of it: or, "they shall be satisfied", that they have an interest in it; and so satisfied with it, that they shall never seek for any other righteousness, as a justifying one, in the sight of God; this being full, perfect, sufficient, and entirely complete.