It was a very great honour that Moses was called to when God commissioned him to bring Israel out of Egypt; yet he is with difficulty persuaded to accept the commission, and does it at last with great reluctance, which we should rather impute to a humble diffidence of himself and his own sufficiency than to any unbelieving distrust of God and his word and power. Note, Those whom God designs for preferment he clothes with humility; the most fit for service are the least forward.

I.Moses objects that in all probability the people would not hearken to his voice (Exo 4:1), that is, they would not take his bare word, unless he showed them some sign, which he had not been yet instructed to do. This objection cannot be justified, because it contradicts what God had said (Exo 3:18), They shall hearken to thy voice. If God says, They will, does it become Moses to say, They will not? Surely he means, "Perhaps they will not at first, or some of them will not." If there should be some gainsayers among them who would question his commission, how should he deal with them? And what course should he take to convince them? He remembered how they had once rejected him, and feared it would be so again. Note, 1. Present discouragements often arise from former disappointments. 2. Wise and good men have sometimes a worse opinion of people than they deserve. Moses sad (Exo 4:1), They will not believe me; and yet he was happily mistaken, for it is said (Exo 4:31), The people believed; but then the signs which God appointed in answer to this objection were first wrought in their sight.

II.God empowers him to work miracles, directs him to three particularly, two of which were now immediately wrought for his own satisfaction. Note, True miracles are the most convincing external proofs of a divine mission attested by them. Therefore our Saviour often appealed to his works (as Joh 5:36), and Nicodemus owns himself convinced by them, Joh 3:2. And here Moses, having a special commission given him as a judge and lawgiver to Israel, has this seal affixed to his commission, and comes supported by these credentials.

1.The rod in his hand is made the subject of a miracle, a double miracle: it is but thrown out of his hand and it becomes a serpent; he resumes it and it becomes a rod again, Exo 4:2-4. Now, (1.) Here was a divine power manifested in the change itself, that a dry stick should be turned into a living serpent, a lively one, so formidable a one that Moses himself, on whom, it should seem, it turned in some threatening manner, fled from before it, though we may suppose, in that desert, serpents were no strange things to him; but what was produced miraculously was always the best and strongest of the kind, as the water turned to wine: and, then, that this living serpent should be turned into a dry stick again, this was the Lord's doing. (2.) Here was an honour put upon Moses, that this change was wrought upon his throwing it down and taking it up, without any spell, or charm, or incantation: his being empowered thus to act under God, out of the common course of nature and providence, was a demonstration of his authority, under God, to settle a new dispensation of the kingdom of grace. We cannot imagine that the God of truth would delegate such a power as this to an impostor. (3.) There was a significancy in the miracle itself. Pharaoh had turned the rod of Israel into a serpent, representing them as dangerous (Exo 1:10), causing their belly to cleave to the dust, and seeking their ruin; but now they should be turned into a rod again: or, thus Pharaoh had turned the rod of government into the serpent of oppression, from which Moses had himself fled into Midian; but by the agency of Moses the scene was altered again. (4.) There was a direct tendency in it to convince the children of Israel that Moses was indeed sent of God to do what he did, Exo 4:5. Miracles were for signs to those that believed not, Co1 14:22.

2.His hand itself is next made the subject of a miracle. He puts it once into his bosom, and takes it out leprous; he puts it again into the same place, and takes it out well, Exo 4:6, Exo 4:7. This signified, (1.) That Moses, by the power of God, should bring sore diseases upon Egypt, and that, at his prayer, they should be removed. (2.) That whereas the Israelites in Egypt had become leprous, polluted by sin, and almost consumed by oppression (a leper is as one dead, Num 12:12), by being taken into the bosom of Moses they should be cleansed and cured, and have all their grievances redressed. (3.) That Moses was not to work miracles by his own power, nor for his own praise, but by the power of God and for his glory; the leprous hand of Moses does for ever exclude boasting. Now it was supposed that, if the former sign did not convince, this latter would. Note, God is willing more abundantly to show the truth of his word, and is not sparing in his proofs; the multitude and variety of the miracles corroborate the evidence.

3.He is directed, when he shall come to Egypt, to turn some of the water of the river into blood, Exo 4:9. This was done, at first, as a sign, but, not gaining due credit with Pharaoh, the whole river was afterwards turned into blood, and then it became a plague. He is ordered to work this miracle in case they would not be convinced by the other two. Note, Unbelief shall be left inexcusable, and convicted of a wilful obstinacy. As to the people of Israel, God had said (Exo 3:18), They shall hearken; yet he appoints these miracles to be wrought for their conviction, for he that has ordained the end has ordained the means.

His hand was leprous as snow - That is, the leprosy spread itself over the whole body in thin white scales; and from this appearance it has its Greek name λεπρα, from λεπις, a scale. Dr. Mead says, "I have seen a remarkable case of this in a countryman, whose whole body was so miserably seized with it, that his skin was shining as if covered with snow; and as the surfuraceous scales were daily rubbed off, the flesh appeared quick or raw underneath." The leprosy, at least among the Jews, was a most inveterate and contagious disorder, and deemed by them incurable. Among the heathens it was considered as inflicted by their gods, and it was supposed that they alone could remove it. It is certain that a similar belief prevailed among the Israelites; hence, when the king of Syria sent his general Naaman, to the king of Israel to cure him of his leprosy, he rent his clothes, saying, Amos I God, to kill and to make alive, that this man doth send unto me to recover a man of his leprosy? Kg2 5:7. This appears, therefore, to be the reason why God chose this sign, as the instantaneous infliction and removal of this disease were demonstrations which all would allow of the sovereign power of God. We need, therefore, seek for no other reasons for this miracle: the sole reason is sufficiently obvious.

And he said, put thine hand into thy bosom again,.... With the leprosy on it:

and he put his hand into his bosom again, and plucked it out of his bosom; quickly after he had put it in:

and, behold, it was turned again as his other flesh; it was cured of the leprosy, and recovered its colour, and was as sound as before, and as any other part of his body. This was a very astonishing miracle, that he should be at once smote with a leprosy; that this should be only in his hand, and not in any other part of his body; and that it should be cured immediately, without the use of any means; and by this miracle Moses, and the Israelites, might be instructed and confirmed in the power of God, that he that could so suddenly inflict such a disease, and so easily cure it, was able to deliver them out of captivity, which was as death; and that however until Moses might be in himself to be a deliverer of the people, signified by his weak and leprous hand, yet being quickened and strengthened by the Lord, would be able to answer to the character; though, after all, the deliverance must be imputed not to his hand and power, but to the mighty hand and power of God.

Put now thine hand into thy bosom--the open part of his outer robe, worn about the girdle.