“Blessed are they that mourn: for they shall be comforted.”
King James Version (KJV)
5:4 They that mourn - Either for their own sins, or for other men's, and are steadily and habitually serious. They shall be comforted - More solidly and deeply even in this world, and eternally in heaven.
Mt 5:4 Blessed [are] they that mourn. Not all mourners, for there is "a sorrow of this world that worketh death". Godly sorrow is meant, a mourning over sinfulness. See 2Co 7:10.