Synopsis of the Books of the Bible, by John Nelson Darby, [1857-62], at sacred-texts.com
The following commentary covers Chapters 30 and 31.
Having thus established the priesthood, and the relationship of the people with God who dwelt in the midst of them, the intercession of Christ in grace (all that was in Him ascending as a sweet savour to Jehovah), is presented (Exo 30:1-10); and His service in making the manifestation of God in the Spirit shine forth (Exo 30:7). The people were identified with this service through redemption (Exo 30:11-16). They could neither be there, nor serve [See Note #1]; but they were all represented as redeemed. We then have the laver between the brazen altar and the tabernacle-purification [See Note #2] for communion with God, and for service to Him therein: the hands and feet (for us only the feet, as our walk alone is concerned), every time they took part in it.
Finally, we have the oil and the incense, the fragrant oil, which were for priests only: the nature of man, as man, or his natural condition in the flesh could not partake of it. The incense typifies the precious perfume of the graces of Christ, the savour of divine graces manifested, and a sweet odour in the world in man. He alone answers to it, though we may seek of and from Him to walk in them.
The institution and obligation of the sabbath was associated with the tabernacle of the congregation, as a sign, as it had been with every form of relationship between God and His people: for to be made partakers of God's rest is what distinguishes His people. In fine, God gave Moses the two tables of the law.
Note #1
The places were seen; but not our entrance into them, with all the rent veil brings with it.
Note #2
It was the washing of water by the word, the purification of the worshipper (first, of the heart) to constitute him one by being born again of the word. But this was not the laver. The priests had their bodies washed first to be such, but it is not said this was in the laver. There they washed their hands and their feet, when they had come into priestly service by the sacrifices, being already washed as to their bodies. That is, they were priests already when they washed their hands and feet in the laver; their bodies had been washed, and the consecrating sacrifices offered; and then in respect of practice, according to the purity of divine life by the Spirit, there was the washing through the word, and especially if they had failed (compare John 13). For communion requires not only acceptance but purification. Without this the presence of God acts on the conscience, not in giving communion, but in shewing the defilement. Christ, even as a man, was pure by nature, and He kept Himself by the words of God's lips. With us, this purity is received from Him; and we must also use the word to purify ourselves. The idea and measure of the purity are the same for Christ and for us: "he that saith he abideth in him ought himself also so to walk, even as he walked"-"to purify himself, even as he is pure." For the ordinary relationship of the people, looked at as worshippers, it was the red heifer (Num. 19); its ashes, which typified this purification on failure, were put into running water; that is, the Holy Spirit applied, by the word, to the heart and conscience, the sufferings of Christ for sin to purify man; sufferings which could have all their moral and purifying power, since the ashes of separation shewed forth that sin had been consumed in the sacrifice of Christ Himself for sin, as to imputation, by the fire of the judgment of God. The blood of the heifer had been sprinkled seven times before the door of the tabernacle-the place where, we have just seen, God met the people; but to worship and serve there must be the actual purification according to the standard of Christ: at least as far as realised, so that the conscience be not bad. This being in His presence, and the judgment of failure, is the means of progress also. Note, the rules as to the red heifer, shew that however it came (for there were cases viewed merely humanly which were inevitable, but, they shew that however it came), God could not have impurity in His presence.