7918.“拿一把牛膝草”表实现洁净所用的外在手段。这从“牛膝草”的含义清楚可知，“牛膝草”是指外在真理，这外在真理是实现洁净的一种手段，如下文所述。经上说，他们要“拿一把牛膝草”，是因为“一把牛膝草”论及真理和对它们的排列（5530，5881，7408节）。“牛膝草”之所以表示作为洁净的一种手段的外在真理，是因为一切属灵洁净都通过真理实现。因为人要从中洁净的尘世和世俗之爱若不通过真理，就无法被识别出来。当主灌输这些真理时，对这些爱，如同对不洁和可诅咒之物的恐惧同时也被灌输进来。这种恐惧的结果是，当某种类似事物进入人的思维时，这种恐惧的感觉就会回来，从而产生对这些事物的厌恶。人就这样通过真理，如同通过一种外在手段被洁净。这就是经上规定要用刀或小剑来行割礼的原因。用火石制成的“小剑”或刀是指实现洁净所用的信之真理（参看2799，7044节）；“割礼”是指从污秽的爱中洁净（2039，2632，3112，3413，4462，7045节）。
由于“牛膝草”具有这种含义，所以它被用来洁净，洁净在内义上表示从虚假与邪恶中洁净，如摩西五经中大麻风的洁净：
祭司为那求洁净的，拿两只洁净的活鸟和香柏木、朱红色线并牛膝草来，把它们蘸于被宰的鸟血中，洒在那求洁净的人身上。（利未记14:4-7）
若房屋中有大麻风，牛膝草同样用来洁净房子（利未记14:49-51）。预备用来洁净的除罪水也涉及香柏木和牛膝草的使用（民数记19:6，18）；“香柏木”表示内在的属灵真理，而“牛膝草”是指外在的（属灵）真理；因此，“香柏木”是洁净 的一种内在手段，而“牛膝草”是一种外在手段。“牛膝草”是一种洁净的手段，这一点明显可见于诗篇：
求你用牛膝草洁净我，我就干净；求你洗涤我，我就比雪更白。（诗篇51:7）
“用牛膝草洁净我”表示外在洁净；“洗涤，比雪更白”表示内在洁净；“雪”和“白”论及真理（3301，3993，4007，5319节）。“牛膝草”表示最低级的真理，“香柏树”表示最高级的真理，这一点从列王纪上中的这些话明显看出来：
所罗门讲论草木，自黎巴嫩的香柏树直到墙上长的牛膝草。（列王记上4:33）
此处“香柏树”表示属于聪明的内在真理，“牛膝草”是指属于聪明的外在真理。
Potts(1905-1910) 7918
7918. And ye shall take a bunch of hyssop. That this signifies an external means by which there is purification, is evident from the signification of "hyssop," as being external truth, which is a means of purification (of which in what follows). It is said that they should "take a bunch of hyssop," because "a bunch" is predicated of truths and their arrangement (n. 5530, 5881, 7408). That "hyssop" denotes external truth as a means of purification, is because all spiritual purification is effected by means of truths. For the earthly and worldly loves from which man is to be purified, are not recognized except by means of truths, and when these are instilled by the Lord, there is also instilled at the same time horror for these loves as for things unclean and damnable, the effect of which is that when anything of the kind flows into the thought, this feeling of horror returns, and consequently aversion for such things. Thus man is purified by truths as by an external means. It was on this account ordered that circumcision should be performed by means of knives or lancets of flint. (That "lancets" or "knives of flint" denote the truths of faith whereby purification is effected, see n. 2799, 7044; and that "circumcision" denotes purification from filthy loves, n. 2039, 2632, 3112, 3413, 4462, 7045.) [2] As "hyssop" has this signification, it was therefore employed in cleansings, which in the internal sense signified purifications from falsities and evils, as in the cleansing of the leprosy, in Moses:
The priest shall take for the leper that is to be cleansed two living clean birds, and cedar wood, and scarlet and hyssop, and shall dip them in the blood of the bird that was killed, and he shall sprinkle upon him that is to be cleansed (Lev. 14:4-7);
and in like manner "in the cleansing of a house, if the leprosy be in it" (verses 49-51). For preparing the water of separation by which cleansings were wrought, cedar wood and hyssop were also employed (Num. 19:6, 18); by "cedar wood" was signified internal spiritual truth, and by "hyssop" external; thus by "cedar" an interior means of purification, by "hyssop" an exterior one. That "hyssop" denotes a means of purification is very manifest in David:
Thou shalt purge me with hyssop, and I shall become clean; Thou shalt wash me, and I shall be whiter than snow (Ps. 51:7);
where "to be purged with hyssop and made clean" denotes external purification; "to be washed and made whiter than snow," internal purification; "snow" and "whiteness" are predicated of truth (n. 3301, 3993, 4007, 5319). That "hyssop" denotes lowest truth, and "cedar" highest truth, is plain from these words in the first book of Kings:
Solomon spoke of woods, from the cedar which is in Lebanon even unto the hyssop that goeth out of the wall (1 Kings 4:33);
where "cedar" denotes internal truth which is of intelligence; and "hyssop," external truth which is of intelligence.
Elliott(1983-1999) 7918
7918. 'And you shall take a bunch of hyssop' means the outward means by which purification is effected. This is clear from the meaning of 'hyssop' as outward truth, the means by which purification is effected, dealt with below. It says that they were to take a bunch of hyssop because 'a bunch' is used to refer to truths and the arrangement of them, 5530, 5881, 7408. The reason why 'hyssop' means outward truth, the means of purification, is that all spiritual purification is effected by means of truths. For the earthly and worldly types of love from which a person has to be purified are not recognized except by means of truths. When these truths are instilled by the Lord a horror of those types of love, as of things unclean and damnable, is also at the same time instilled. The effect this horror has is that when something similar enters the person's thinking the feeling of horror returns, producing a loathing of those types of love. That is how a person is purified by truths, which serve as outward means. This was the reason why it was laid down that knives or 'small swords' made of flint should be used when circumcision took place, 'small swords' or knives made of flint being the truths of faith by means of which purification is effected, see 2799, 7044, and 'circumcision purification from filthy types of love, 2039, 2632, 3412, 3413, 4461, 7045.
[2] Since 'hyssop' had that meaning it was used in cleansings, which in the internal sense meant purifications from falsities and evils, as in the cleansing of leprosy in Moses,
The priest shall take for cleansing a leper two living clean birds, and cedarwood, and scarlet, and hyssop; and he shall dip them in the blood of the slaughtered bird, and sprinkle over the one to be cleansed. Lev 14:4-7.
Hyssop was likewise used in the cleansing of the house, if leprosy was in it, Lev 14:49-51.The preparation of the water of separation by which cleansings were accomplished also involved the use of cedarwood and hyssop, Num 19:6,18. 'Cedarwood' meant inward spiritual truth, whereas 'hyssop' meant outward [spiritual] truth. Thus 'cedarwood' is the means effecting purification more internally, 'hyssop' the means effecting it more externally. That 'hyssop' is a means of purification is plainly evident in David,
You will purge me with hyssop and I shall become clean; You will wash me and I shall be made whiter than snow. Ps 51:7.
'Purging with hyssop and becoming clean' stands for external purification, 'washing and being made whiter than snow' for internal purification, 'snow' and 'whiteness' having reference to truth, 3301, 3993, 4007, 5319. 'Hyssop' means a very low kind of truth and 'cedar' a superior kind of truth, as is evident from the following words in the first Book of Kings, Solomon spoke about trees, from the cedar which is in Lebanon even to the hyssop which comes out of the wall. 1 Kings 4:33.
Here 'the cedar' stands for the internal kind of truth and 'hyssop' for the external kind of truth that belong to intelligence.
Latin(1748-1756) 7918
7918. `Et accipietis fasciculum hyssopi': quod significet medium externum per quod purificatio, constat ex significatione `hyssopi' quod sit verum externum quod medium purificationis, de qua sequitur; dicitur quod `acciperent fasciculum hyssopi' quia `fasciculus' praedicatur de veris et eorum dispositione, n. 5530, 5881, 7408; quod `hyssopus' sit verum externum, quod medium purificationis, est quia omnis purificatio spiritualis fit per vera; amores enim terrestres et mundani (c)e quibus homo purificandus {1}non cognoscuntur nisi per vera, quae cum a Domino insinuantur, etiam simul pro amoribus illis, ut pro immundis et damnandis, horror insinuatur, qui facit ut cum simile influit in cogitationem, redeat horrescentia illa, proinde aversatio pro illis; ita purificatur homo per vera, ut per media externa; quia ita, statutum fuit, ut circumcisio fieret per cultros seu gladiolos petrarum; quod gladioli seu cultri petrarum sint vera fidei per quae purificatio, videatur n. 2799, 7044, et quod circumcisio sit purificatio ab amoribus spurcis, n. 2039, 2632, 3412, 3413, 4462, 7045. 2 Quia `hyssopus' id significabat, ideo adhibebatur in mundationibus quae in sensu interno significabant purificationes a falsis et malis {2}; ut in mundatione leprae, apud Moschen, Accipiet sacerdos pro mundando leproso duas aves viventes mundas, et lignum cedri, et coccineum, et hyssopum; ac intinget illa in sanguinem avis mactatae, et sparget super mundandum, Lev. xiv 4-7:similiter in mundatione domus, si lepra in illa, ibid. vers. 40-51: ad aquam separationis per quam mundabantur, conficiendam, etiam adhibebatur lignum cedri et hyssopus {3}, Num. xix 6, 18; per `lignum cedri' significabatur verum spirituale internum, per `hyssopum' autem externum; ita per `cedrum' medium purificationis interius, per `hyssopum' exterius: quod `hyssopus' sit medium purificationis, patet manifeste apud Davidem, Expiabis me hyssopo, et mundus fiam; lavabis me et prae nive dealbabor, Ps. li 9 [A.V. 7];
`expiare hyssopo et mundus fieri' pro purificatione externa; `lavare et prae nive dealbari' pro purificatione interna; nix et albedo praedicatur de vero, n. 3301, 3993, 4007, 5319; quod `hyssopus' sit verum infimum, et `cedrus' superius, patet (c)ex his in Libro Primo Regum, Schelomo locutus est de lignis a cedro quae in Libano, usque ad hyssopum quae exiens {4}e pariete, v 13 [A.V. iv 33], ubi `cedrus' pro vero quod est intelligentiae interno, et `hyssopus' pro vero quod intelligentiae externo. @1 est, cognoscuntur per vera, cumque vera insinuantur, etiam pro illis ut pro immundis et spurcis, horror insinuatur, qui facit ut cum simile recurrit, redeat horrescentia illa, proinde aversatio; ita purificatur homo per vera ut pro media externa; quia purificatio fit per vera ut per media externa, ideo statutum est$ @2 i quae sunt supradictorum amorum$ @3 i et aqua illa per hyssopum aspergebatur$ @4 in$