Synopsis of the Books of the Bible, by John Nelson Darby, [1857-62], at sacred-texts.com
Exodus Chapter 4
Moses still raises difficulties, and God gives him again signs, remarkable signs. The two first seem to me in their character-types, the first, of sin and of its healing; the second, of power, which, having become Satanic, is taken back, and becomes the rod of God; and then presents that which refreshes, coming from God, as having become judgment and death. But we must note here the difference of what was then given to Moses and what occurred in Egypt. Here in the two personal signs there is first restoration (the leprosy is healed), and then power from which Moses fled becomes the rod of God in his hand The water becoming blood is simple judgment. In Egypt the first is not found, he acted for God there, but there was a much larger development of the two last signs. The persona healing, that is, and removal of sin there was nothing of. But power completely destroys all manifestation of Satanic power and the worshipped source of wealth for the flesh and the world became death and judgment to it. But Moses refuses still and the wrath of God is kindled against him; yet He acts in mercy, in a way, however, humbling to Moses, with whom h now joins Aaron his brother whom He had already prepared for that, and who had come out of Egypt to meet him; for the folly of His children, while it is to their shame and to their loss accomplishes the purposes of God.
Whatever may be the power of Him that delivers, it is necessary that circumcision should be found in him who is interested in, and who is used as an instrument of the deliverance; for the Saviour-God is a God of holiness; it is in holiness and in judging sin, that He delivers: and acting in holiness He does not suffer sin in those who are co-workers for Him with whom He is in contact; for He comes out of His place in judgment. For us the question is of being dead to sin, the true circumcision; our Moses is a bloody husband to her who has to do with him. God cannot use the flesh in the fight against Satan. He cannot suffer it Himself, for He is in His place in judgment. Satan also would have power over it, and of right; God therefore puts it to death Himself, and this is done for us on the cross, where He who knew no sin was made sin for us (compare Rom 8:3). And He wills that this should be accomplished in us also. This is true of those who compose the assembly; but they can reckon themselves dead. We bear about in the body the dying of the Lord Jesus [See Note #1]. It will be true in one way more evidently, in judgment at the last day, when the Lord pleads with all flesh, and identifies Himself with those who have not taken part spiritually in the fellowship of Christ's sufferings, the Christian's place. God will purge Jerusalem by the spirit of burning.
Note #1
In Colossians 3 we find God's judgment of him in whom Christ (compare Rom 8:10); in Romans 6 faith reckons it so: in 2 Corinthians 4 it is practically realised. And God proves the faith, but to confirm the soul in it. See 2 Corinthians 1 and 4.