(Heb borith mekabbeshim, i.e., "alkali of those treading cloth"). Mention is made (Pr 25:20; Jer 2:22) of nitre and also (Mal 3:2) of soap (Heb borith) used by the fuller in his operations. Nitre is found in Syria, and vegetable alkali was obtained from the ashes of certain plants. (See Soap.)
Whoso singeth a song to a heavy heart, clotheth him with rags in the cold, and poureth vinegar upon chalk.
Yea, and that so sore, that though thou washest thee with Nitre and makest thyself to savour with that sweet smelling herb of Borith: yet in my sight thou art stained with thy wickedness, sayeth the LORD thy God.
Who shall endure in the day of his coming, or who shall stand to behold him? For he is as trying fire, and as the herb that fullers scour withal.