Malachi 4:2

In contrast, the Israelites who feared Yahweh (Malachi 1:14; Malachi 3:5; Malachi 3:16-17) would experience a reign of righteousness compared here to sunshine (cf. Isaiah 60:1-3). The sun can blister, but it can also bless, and its blessing effect is in view here. The prophet evidently visualized the sunrays like the wings of a bird stretching over the earth. This righteous day would have a healing effect on the inhabitants of the earth, healing them, and the planet, from the harmful effects of past millennia of sin (cf. Isaiah 53:5).

Some expositors have understood "the sun of righteousness" to be a messianic title, but it seems best to view it as a description of the day of blessing that Messiah will bring, the Millennium. The New Testament never referred to Jesus Christ as "the sun of righteousness." The figure of vigorous calves cavorting in open pasture after having been cooped up in a stall pictures the joy and freedom that the righteous will enjoy in that day (cf. Isaiah 65:17-25; Hosea 14:4-7; Amos 9:13-15; Zephaniah 3:19-20).