Mateus 5:4

They that mourn. — The verb is commonly coupled with weeping (Marcos 16:10; Lucas 6:25; Tiago 4:9; Apocalipse 18:15). Here, as before, there is an implied, though not an expressed, limitation. The “mourning” is not the sorrow of the world that worketh “death” (2 Coríntios 7:10) for failure, suffering, and the consequences of sin, but the sorrow which flows out in the tears that cleanse, the mourning over sin itself and the stain which it has left upon the soul.

They shall be comforted. — The pronoun is emphatic. The promise implies the special comfort (including counsel) which the mourner needs; “comforted” he shall be with the sense of pardon and peace, of restored purity and freedom. We cannot separate the promise from the word which Christendom has chosen (we need not now discuss its accuracy) to express the work of the Holy Ghost the Comforter, still less from the yearning expectation that then prevailed among such of our Lord’s hearers as were looking for the “consolation” — i.e., the “comfort” — of Israel (Lucas 2:25).