Who may abide the day of his comings? They had expected him to come and judge the heathen; the prophet warns them that they themselves shall be first judged (comp. Amos 5:18). "Malachi, like John the Baptist, sees the future Judge in the present Saviour" (Wordsworth); Joel 2:11.
Who shall stand! Who can stand up under the burden of this judgment? The Vulgate Version, Quis stabit ad videndum eum? points to the brightness of his presence, which eye of man cannot endure. Like a refiner's fire, which separates the precious metal from the refuse.
So the Lord at his coming shall sever the good among men from the evil (Isaiah 1:25; Jeremiah 6:29; Zechariah 13:9). Like fullers' soap; Septuagint, ὡς ποιὰ πλυνόντων, "as the grass of washers;" Vulgate, quasi herba fullonum, What is to be understood exactly by the "soap" (borith), washing herb, is not known.
Probably the ashes of some plant yielding a lye, like carbonate of soda, are meant. Such plants are met with on the shores of the Mediterranean and Dead Seas, and at this day large quantities of alkalies are extracted from them and exported in different directions.
The Lord shall wash away all that is filthy (comp. Matthew 3:10, Matthew 3:12).