I. "Blessed are the merciful." The object of the Beatitudes is to bring out one particular quality, without commending the other qualities which may exist in the same character. We see many men of very imperfect morality, and yet in whom this quality of mercy is such that we feel that, if it were universal among mankind, the whole world would be the happier for it, and that in those in whom it is found it is a redeeming virtue in the proper sense of the word a virtue which redeems from condemnation and detestation the whole character in which it is found embedded. We cannot believe that the generous and merciful acts of such men as these can ever be lost in the sight of God by reason of the other faults with which they are surrounded. It is the very quality on which our Saviour's blessing has been most distinctly pronounced. "Forgive," He says, "and ye shall be forgiven." And the feeling of posterity, and the feeling of contemporaries, is, after all, some slight index of what we may call in this respect the final judgment of God.
II. "Blessed are the pure in heart." The words may bear a twofold meaning pure, disinterested love of truth, and pure, clean aversion to everything that defiles. (1) Pure love of truth. How very rare, yet how very beneficent! Look at Sir Isaac Newton, the most famous name which Westminster Abbey contains. It was said by those who knew him that he had the whitest soul they had ever known the whitest especially in this, that no consideration ever came across his desire of propounding and of ascertaining the exact truth on whatever subject he was engaged. (2) Purity from all that defiles and stains the soul. Filthy thoughts, filthy actions, filthy words we know what they are without attempting to describe them. Of all the obstacles which may intervene between us and an insight into the virtue which is the nature of the Invisible and the Divine, nothing presents so coarse and so thick a veil as, on the one hand, a false, artificial, crooked way of looking at truth, and, on the other hand, at the indulgence of brutal and impure passions, which lower our sight; and nothing can so clear up our better thoughts, nothing leave our minds so open to receive the impression of what is good and noble, as the single eye and the pure conscience.
A. P. Stanley, Christian World Pulpit,vol. xx., p. 24.