SOAP ( bôrîth ) occurs in EV [Note: English Version.] (AV [Note: Authorized Version.] ‘ sope ’) only in Jeremiah 2:22 (washing of the person) and Malachi 3:2 (operations of the fuller). Properly bôrîth denotes simply ‘that which cleanses.’ The cognate word bôr is commonly rendered ‘cleanness,’ but in Job 9:30 , Isaiah 1:25 RVm [Note: Revised Version margin.] gives ‘ lye .’ Soap in the modern sense of the word was unknown in OT times, and we do not know what precisely is referred to by bôrîth . As in Jeremiah 2:22 nether (AV [Note: Authorized Version.] ‘nitre’ [wh. see]), a mineral alkali, is set in antithesis to bôrîth , it is supposed that the latter was some kind of vegetable alkali which, mixed with oil, would serve the purposes of soap. This may be confirmed by the fact that in Jeremiah 2:22 and Malachi 3:2 LXX [Note: Septuagint.] renders bôrîth by poia = ‘grass.’
J. C. Lambert.