“But who can endure

The day of his coming?

Who can stand

when he appears?

Yahweh is

Like a refiner’s fire,

Like fullers’ soap.”

The day of Yahweh would be difficult for everyone.  Who could endure it?  Who would be able to stand up when it happened.  This day of Yahweh was going to be like the fire that refined precious metals.  This day was going to be like being rubbed with fuller’s soap.  A fuller was someone who made clothes white.  He used some kind of alkali, like a lye soap or a modern-day bleach.  This fuller soap was very strong.