Distribution of the word across the Bible: Jeremiah (1), Malachi (1)
Jeremiah 2:22 — For though thou wash thee with nitre, and take thee much soap (בֹּרִ֑ית), yet thine iniquity is marked before me, saith the Lord GOD.
Malachi 3:2 — But who may abide the day of his coming? and who shall stand when he appeareth? for he is like a refiner’s fire, and like fullers’ soap (וּכְבֹרִ֖ית):