Bible Dictionaries
Lye

Holman Bible Dictionary

Substance used for cleansing purposes from the earliest times. Two Hebrew words are used in the Old Testament for lye. Nethar probably refers to sodium bicarbonate. This material occurs naturally and is referred to by ancient writers as appearing in Egypt and Armenia.

Bor likely refers to potassium carbonate and is sometimes called vegetable lye. It is a strongly alkaline solution made by burning certain plants like soapwort and leaching the lye from the ashes. This was the type of lye normally used in Palestine, for there are no known deposits of sodium bicarbonate there. The same Hebrew spelling also means, “purity” ( Psalm 18:20 ,Psalms 18:20,18:24 ) leading to confusion in English translations.

The term “lye” is used in the English Bible in a figurative sense on at least three occasions. In each case it is used as a means for the removal of sin. Job recognized the depth of his own sin. Nothing, not even lye, could cleanse his dirty hands (Job 9:30 NAS, NRSV, REB; compare NIV, “washing soda.”). In Isaiah 1:25 , God promised to redeem His corrupt people, but they would have to undergo a painful cleansing time first. Lye (NAS, NRSV; compare REB, “potash”) would remove the sin in their lives if they repented. Only then would they be considered righteous. In Jeremiah 2:22 God warned Judah that they could not remove their sin, not even with lye (NRSV, NAS; compare KJV, “niter”; NIV, REB, “soda”). The only recourse was repentance toward God.

Bradley S. Butler