We have already seen, and the Prophet will often repeat the same thing, -- that the people were become so refractory that they would not willingly give way to any reproofs; for they were almost all of such a hard front, and so obdurate in their wickedness, that they dared insolently to raise objections against the prophets; whenever they severely reproved them: "What! Are not we God's holy people? Has he not chosen us? Are we not the holy seed of Abraham?" It was therefore necessary for the prophets to apply a hard wedge to a hard knot, as they commonly say. As, then, the Israelites were like a knotty wood, it was necessary to strike hard their obstinacy. On this account Jeremiah now says, Even if thou wert to wash thyself with nitre, and multiply to thee borith, yet thine iniquity would be before me marked; that is, "Ye effect nothing when ye set forth various pretences for the sake of excusing your impiety: wash yourselves, but your iniquity remains marked before me." The Prophet speaks in the person of God, that he might add more weight to the denunciation he pronounced on the Israelites, and by which he reduced to nothing their self -- flatteries, according to what has been already stated. By nitre and borith they removed stains in cloth; and hence borith is often mentioned in connection with fullers. But there is no need of a laborious inquiry, whether it was an herb or dust, or something of that kind; for as to what is meant, it is generally agreed that the Prophet teaches us by this metaphor, -- that hypocrites gain nothing by setting up their pretences, that they may escape, when God condemns them. Hence he says, that all their attempts would be vain and fruitless. How so? Because their iniquity remained unwashed; that is, because they could not remove by washing what is imprinted. Spots or stains can indeed be cleansed or washed away by soap or other things; but when the stain is inward, and imprinted within, washing will avail nothing, for the marks are so deep that some more efficacious remedy must be adopted. So now the Prophet says, that the stains were imprinted, and therefore could not be washed away or cleansed by soap or borith. [1] But the Prophet says, that the stains were marked, or stamped, before God; for it was a common thing with the Israelites to clear themselves from every blame; nay, so great was their audacity, that they openly opposed the prophets, as though some great wrong was done to them; and they called the prophets accusers and slanderers, Hence he says, Thine iniquity is stamped before me? [2] that is, "However thou mayest by self -- flatteries deceive thyself, and hidest thy sins before the world, yet thou gainest nothing; for in my sight thine iniquity ever remains stamped." He afterwards adds --

Footnotes

1 - What we call "nitre" is different from the "nitron" here mentioned. The verb, from which the noun is derived, means to loosen, to set free: and hence the article called nitron dissolves in water, and loosens and washes away spots and stains. Borith was an herb, which, being burnt, and its ashes dissolved in water, had a strong cleansing power. -- Ed.

2 - The verb rendered "stamped" is only found here in Niphel, but, as a participial noun, it seems to mean gold stamped or marked to shew its genuineness. See Psalm 45:9; Proverbs 25:12. A stain or spot is not what it signifies, as given by the Septuagint and the Vulgate, nor "blot," according to Blarney; but it refers to the stamp or mark imprinted on a hard metal, such as gold: and this idea alone corresponds with the other parts of the verse. A stain, a spot, or a blot, might be cleansed by abstergents, but not a mark stamped on a metal, -- But thou washest thyself with nitron, And multipliest for thyself fuller's ashes: Stamped is thine iniquity before me, Saith the Lord Jehovah. -- Ed.

Nitre - Or, natron, a mineral alkali, found in the Nile valley, where it effloresces upon the rocks and surfaces of the dykes, and in old time was carefully collected, and used to make lye for washing (see Proverbs 25:20).
Sope - A vegetable alkali, now called "potash," because obtained from the ashes of plants. Its combination with oils, etc., to form soap was not known to the Hebrews until long after Jeremiah's time, but they used the lye, formed by passing water through the ashes. Thus then, though Israel use both mineral and vegetable alkalies, the most powerful detergents known, yet will she be unable to wash away the stains of her apostasy.
Thine iniquity is marked - i. e., as a stain.

For though thou wash thee with nitre - It should be rendered natar or natron, a substance totally different from our nitre. It comes from the root נתר nathar, to dissolve, loosen, because a solution of it in water is abstersive, taking out spots, etc., from clothes. It is still used in the east for the purpose of washing. If vinegar be poured on it, Dr. Shaw says, a strong effervescence is the immediate consequence, which illustrates Proverbs 25:20 : "The singing of songs to a heavy heart is like vinegar upon natron;" that is, there is no affinity between them; opposition and strife are occasioned by any attempt to unite them.
Thine iniquity is marked before me - No washing will take out thy spots; the marks of thy idolatry and corruption are too deeply rooted to be extracted by any human means.

For though thou shalt wash thee with (g) lye, and take thee much soap, [yet] thy iniquity is marked before me, saith the Lord GOD.
(g) Though you use all the purifications and ceremonies of the law, you cannot escape punishment.

For though thou wash thee with nitre,.... The word "nitre", is only used in this place and in Proverbs 25:20 and it is hard to say what it is. Kimchi and Ben Melech observe, that some say it is what is called "alum"; and others that it is a dust with which they wash the head, and cleanse everything; and so Jarchi says it is a kind of earth used in cleaning garments; and "nitre" is mentioned by the Misnic doctors (s) among those things which are used for the washing of garments, and taking spots out of them; though about what it is they are not agreed; and it seems the nitre of the ancients is unknown to us (t); and saltpetre is put in the room of it; and some render the word here "saltpetre"; and Pliny (u) observes, that nitre does not much differ from salt, and ascribes to it a virtue of eating out filth, and removing it; so Aristotle (w) reports of the lake Ascania; that its water is of such a nitrous quality, that garments, being put into it, need no other washing. Nitre has its name from "to loose", because it looses the filth, and cleanses from it:
and take thee much soap. The Septuagint render it, "herb"; and the Vulgate Latin version, "the herb borith"; which is the Hebrew word here used; and about the sense of which there is some difficulty. Kimchi and Ben Melech say some take it to be the same with what is called "soap"; so Jarchi; and others, that it is an herb with which they wash, the same that is called fullers' herb; but whether it is soap, or fullers' herb, or fullers' earth, as others, it is certain it is something fullers used in cleaning garments, as appear from Malachi 3:2, where the same word is used, and fullers made mention of as using what is signified by it. It has its name from which signifies to "cleanse" and "purify". The sense is, let this backsliding and degenerate people take what methods they will to cleanse themselves from their sins, as by their ceremonial ablutions and sacrifices, which was the usual method they had recourse to, to purify themselves, and in which they rested:
yet thine iniquity is marked before me, saith the Lord God; or, "will retain its spots" (x) these remain; the filth is not washed away; the iniquity is not hid and covered; it appears very plain and manifest;
yea, shines like gold; or, "is gilded" (y); as the word used signifies. It is of too deep a die to be removed by such external things; nothing but the blood of Christ can cleanse from sin, take away its filth, removes its guilt, and cover it out of the sight of God, so that it can be seen no more. The Targum is,
"for if you think to be cleansed from your sins, as they cleanse with nitre, or make white with "borith", or soap; lo, as the mark of a spot which is not clean, so are your sins multiplied before me, saith the Lord God.''
(s) Misn. Sabbat, c. 9. sect. 5. & Nidda, c. 9. sect. 6. & Maimon & Bartenora in ib. & in Misn. Celim, c. 10. sect. 1. (t) Schroder. Pharmacopoeia, l. 3. c. 23. p. 140. (u) Nat. Hist. l. 31. c. 10. (w) Opera, vol. 1, de Mirabil. p. 705. (x) "Maculas tamen retinebit iniquitas tua", Schmidt. (y) "nitet, vel splendet, instar anri", Piscator; "obducat se auro insigni", Junius & Tremellius; so Gussetius renders the word, "inaurari, auro ebduci"; and who rightly observes, that whatever is glided, or covered with gold, the more it is washed with nitre, or soap, the brighter it will appear; and so, whatever other methods are taken to wash away sin, but seeking for justification by the grace of God in Christ, it will be but the more manifest, Ebr. Comment. p. 410.

nitre--not what is now so called, namely, saltpeter; but the natron of Egypt, a mineral alkali, an incrustation at the bottom of the lakes, after the summer heat has evaporated the water: used for washing (compare Job 9:30; Proverbs 25:20).
soap--potash, the carbonate of which is obtained impure from burning different plants, especially the kali of Egypt and Arabia. Mixed with oil it was used for washing.
marked--deeply ingrained, indelibly marked; the Hebrew, catham, being equivalent to cathab. Others translate, "is treasured up," from the Arabic. MAURER from a Syriac root, "is polluted."

Though thou adoptedst the most powerful means of purification, yet couldst thou not purify thyself from the defilement of thy sins. נתר, natron, is mineral, and בּרית vegetable alkali. נכתּם introduces the apodosis; and by the participle a lasting condition is expressed. This word, occurring only here in the O.T., sig. in Aram. to be stained, filthy, a sense here very suitable. לפני, before me, i.e., before my eyes, the defilement of thy sins cannot be wiped out. On this head see Isaiah 1:18; Psalm 51:4, Psalm 51:9.

Nitre - Though interpreters do greatly vary in describing what is particularly meant here by Nitre and Soap, and would be superfluous to mention here; yet all agree, they are some materials that artists make use of for cleansing away spots from the skin. The blot of this people is by no art to be taken out; nor expiated by sacrifices; it is beyond the power of all natural and artificial ways of cleansing. Marked - Thy filthiness is so foul that it leaves a brand behind which cannot be hid or washed out, but will abide, Jeremiah 17:1.