A much deeper meaning underlies the profound expression which God now commands Moses to employ; and although it must await consideration at a future time, the progressive education of Moses himself is meantime to be observed. At first he is taught that the Lord is the God of their fathers, in whose descendants He is therefore interested. Then the present Israel is His people, and valued for its own sake. Now he hears, and is bidden to repeat to Pharaoh, the amazing phrase, “Israel is My son, even My firstborn: let My son go that he may serve Me; and if thou refuse to let him go, behold I will slay thy son, even thy firstborn.” Thus it is that infant faith is led from height to height. And assuredly there never was an utterance better fitted than this to prepare human minds, in the fulness of time, for a still clearer revelation of the nearness of God to man, and for the possibility of an absolute union between the Creator and His creature. It was on his way into Egypt, with his wife and children, that a mysterious interposition forced Zipporah reluctantly and tardily to circumcise her son. The meaning of this strange episode lies perhaps below the surface, but very near it. Danger in some form, probably that of sickness, pressed Moses hard, and he recognised in it the displeasure of his God. The form of the narrative leads us to suppose that he had no previous consciousness of guilt, and had now to infer the nature of his offence without any explicit announcement, just as we infer it from what follows. If so, he discerned his transgression when trouble awoke his conscience; and so did his wife Zipporah. Yet her resistance to the circumcision of their younger son was so tenacious, with such difficulty was it overcome by her husband’s peril or by his command, that her tardy performance of the rite was accompanied by an insulting action and a bitter taunt. As she submitted, the Lord “let him go”; but we may perhaps conclude that the grievance continued to rankle, from the repetition of her gibe, “So she said, A bridegroom of blood art thou because of the circumcision.” The words mean, “We are betrothed again in blood,” and might of themselves admit a gentler, and even a tender significance; as if, in the sacrifice of a strong prejudice for her husband’s sake, she felt a revival of “the kindness of her youth, the love of her espousals.” For nothing removes the film from the surface of a true affection, and makes the heart aware how bright it is, so well as a great sacrifice, frankly offered for the sake of love. But such a rendering is excluded by the action which went with her words, and they must be explained as meaning, This is the kind of husband I have wedded: these are our espousals. With such an utterance she fades almost entirely out of the story: it does not even tell how she drew back to her father; and thenceforth all we know of her is that she rejoined Moses only when the fame of his victory over Amalek had gone abroad.