*Minor differences ignored. Grouped by changes, with first version listed as example.
Not as Moses Paul is not reasoning as to the intention of Moses. For as it was his office, to publish the law to his people, so, there can be no doubt that he was desirous, that its true meaning should be apprehended by all, and that he did not intentionally involve his doctrine in obscurity, but that the fault was on the part of the people. As, therefore, he could not renew the minds of the hearers, he was contented with faithfully discharging the duty assigned to him. Nay more, the Lord having commanded him to put a veil between his face and the eyes of the beholders, he obeyed. Nothing, therefore, is said here to the dishonor of Moses, for he was not required to do more than the commission, that was assigned to him, called for. In addition to this, that bluntness, or that weak and obtuse vision, of which Paul is now speaking, is confined to unbelievers exclusively, because the law though wrapt up in figures,  did nevertheless impart wisdom to babes, Psalm 19:7 
1 - "Figures et ombres;" -- "Figures and shadows."
2 - "The clause rendered in our authorized version -- making wise the simple, is rendered by Calvin, instructing the babe in wisdom. In Tyndale's Bible the reading is, And giveth wisdom even unto babes.' Babes is the word used in most of the versions." -- Calvin on the Psalms, vol. 1, p. 317, n. 2. -- Ed.
And not as Moses - Our conduct is not like that of Moses. We make no attempt to conceal anything in regard to the nature, design, and duration of the gospel. We leave nothing designedly in mystery.
Which put a vail over his face - That is, when he came down from Mount Sinai, and when his face shone. Exodus 34:33, "and until Moses had done speaking with them, he put a vail on his face." He put off this veil whenever he went to speak with God, but put on again when he delivered his commands to the people, What was the design of this, Moses has not himself declared. The statement which he makes in Exodus would lead us to suppose that it was on account of the exceeding brightness and dazzling splendor which shone around him, and which made it difficult to look intently upon him; and that this was in part the reason, even Paul himself seems to intimate in 2-Corinthians 3:7. He, however, in this verse intimates that there was another design, which was that he might be, as Doddridge expresses it, "a kind of type and figure of his own dispensation."
That the children of Israel - Mr. Locke understands this of the apostles, and supposes that it means, "We do not veil the light, so that the obscurity of what we deliver should hinder the children of Israel from seeing in the Law which was to be done away, Christ who is the end of the Law." But this interpretation is forced and unnatural. The phrase rendered "that" πρός τὸ pros to evidently connects what is affirmed here with the statement about Moses; and shows that the apostle means to say that Moses put the veil on his face in order that the children of Israel should not be able to see to the end of his institutions. That Moses had such a design, and that the putting on of the veil was emblematic of the nature of his institutions, Paul here distinctly affirms. No one can prove that this was not his design; and in a land and time when types, and emblems, and allegorical modes of speech were much used, it is highly probable that Moses meant to intimate that the end and full purpose of his institutions were designedly concealed.
Could not stedfastly look - Could not gaze intently upon (ἀτενίσαι atenisai); see the note on 2-Corinthians 3:7. They could not clearly discern it; there was obscurity arising from the fact of the designed concealment. He did not intend that they should clearly see the full purport and design of the institutions which he established.
To the end - (εἰς τὸ τέλος eis to telos). Unto the end, purpose, design, or ultimate result of the Law which he established. A great many different interpretations have been proposed of this. The meaning seems to me to be this: There was a glory and splendor in that which the institutions of Moses typified, which the children of Israel were not permitted then to behold. There was a splendor and luster in the face of Moses, which they could not gaze upon, and therefore he put a veil over it to diminish its intense brightness. In like manner there was a glory and splendor in the ultimate design and scope of his institutions, in that to which they referred, which they were not then "able," that is, prepared to look on, and the exceeding brightness of which he of design concealed. This was done by obscure types and figures, that resembled a veil thrown over a dazzling and splendid object.
The word "end," then, I suppose, does not refer to termination, or close, but to the "design, scope, or purpose" of the Mosaic institutions; to that which they were intended to introduce and adumbrate. that end was the Messiah, and the glory of his institutions; see the note on Romans. 10: "Christ is the end of the Law." And the meaning of Paul, I take to be, is, that there was a splendor and a glory in the gospel which the Mosaic institutions were designed to typify, which was so great that the children of Israel were not fully prepared to see it, and that he designedly threw over that glory the veil of obscure types and figures; as he threw over his face a veil that partially concealed its splendor. Thus, interpreted there is a consistency in the entire passage, and very great beauty. Paul, in the following verses, proceeds to state that the veil to the view of the Jews of his time was not removed; that they still looked to the obscure types and institutions of the Mosaic Law rather than on the glory which they were designed to adumbrate; as if they should choose to look upon the veil on the face of Moses rather than on the splendor which it concealed.
Of that which is abolished - Or rather to be abolished, τοῦ καταργουμένου to katargoumenou), whose nature, design, and intention it was that it should be abolished. It was never designed to be permanent; and Paul speaks of it here as a thing that was known and indisputable that the Mosaic institutions were designed to be abolished.
And not as Moses - The splendor of Moses' countenance was so great that the Israelites could not bear to look upon his face, and therefore he was obliged to veil his face: this, it appears, he did typically, to represent the types and shadows by which the whole dispensation of which he was the minister was covered. So that the Israelites could not steadfastly look - could not then have the full view or discernment of that in which the Mosaic dispensation should issue and terminate.
(4) And not as Moses, [which] put a vail over his face, that the children of Israel could not stedfastly look to the (m) end of that which is abolished:
(4) He expounds along the way the allegory of Moses' covering, which was a token of the darkness and weakness that is in men, who were rather dulled by the bright shining of the Law then given. And this covering was taken away by the coming of Christ, who enlightens the hearts, and turns them to the Lord, that we may be brought from the slavery of this blindness, and set in the liberty of the light by the power of Christ's Spirit.
(m) Into the very bottom of Moses' ministry.
And not as Moses, which put a veil over his face,.... This he did, because there was such a glory upon his face when he came down from the mount, that the Israelites could not bear to look upon him; and also to take off that dread of him which was upon them, for they were afraid to come nigh him; and that so they might be able to hearken and attend to the words of the law, he delivered to them: the account of Moses's putting on this veil is in Exodus 34:33 where Onkelos renders it by , "the house of the face", or a "mask": and Jarchi on the place says it was a "garment", which he put before his face; and both the Targums of Jonathan and Jerusalem call it "a linen cloth": now this veil upon his face had a mystery in it; it was an emblem of the Gospel being veiled under the law, and of the darkness and obscurity of the law in the business of life and salvation; and also of the future blindness of the Jews, when the glory of the Gospel should break forth in the times of Christ and his apostles; and which was such,
that the children of Israel, the Jews, as in the times of Moses, so in the times of Christ and his apostles,
could not steadfastly look to; not upon the face of Moses, whose face was veiled; not that they might not look, but because they could not bear to look upon him; but they could not look
to the end of that which is abolished; that is, to Christ, who is the end of the law, which is abrogated by him: to him they could not look, nor could they see him to be the fulfilling end of the law for righteousness; which being fulfilled, is done away by him; and this because of the blindness of their hearts, of which blindness the veil on Moses' face was typical: though the Alexandrian copy and the Vulgate Latin version read, "to the face of him which is abolished".
We use no disguise, "as Moses put a veil over his face, that the children of Israel might not look steadfastly upon the end of that which was to be done away" [ELLICOTT and others]. The view of Exodus 34:30-35, according to the Septuagint is adopted by Paul, that Moses in going in to speak to God removed the veil till he came out and had spoken to the people; and then when he had done speaking, he put on the veil that they might not look on the end, or the fading, of that transitory glory. The veil was the symbol of concealment, put on directly after Moses' speaking; so that God's revelations by him were interrupted by intervals of concealment [ALFORD]. But ALFORD'S view does not accord with 2-Corinthians 3:7; the Israelites "could not look steadfastly on the face of Moses for the glory of his countenance." Plainly Moses' veil was put on because of their not having been able to "look steadfastly at him." Paul here (2-Corinthians 3:13) passes from the literal fact to the truth symbolized by it, the blindness of Jews and Judaizers to the ultimate end of the law: stating that Moses put on the veil that they might not look steadfastly at (Christ, Romans 10:4) the end of that (law) which (like Moses' glory) is done away. Not that Moses had this purpose; but often God attributes to His prophets the purpose which He has Himself. Because the Jews would not see, God judicially gave them up so as not to see. The glory of Moses' face is antitypically Christ s glory shining behind the veil of legal ordinances. The veil which has been taken off to the believer is left on to the unbelieving Jew, so that he should not see (Isaiah 6:10; Acts 28:26-27). He stops short at the letter of the law, not seeing the end of it. The evangelical glory of the law, like the shining of Moses' face, cannot be borne by a carnal people, and therefore remains veiled to them until the Spirit comes to take away the veil (2-Corinthians 3:14-17) [CAMERON].
And we do not act as Moses did, who put a veil over his face - Which is to be understood with regard to his writings also. So that the children of Israel could not look steadfastly to the end of that dispensation which is now abolished - The end of this was Christ. The whole Mosaic dispensation tended to, and terminated in, him; but the Israelites had only a dim, wavering sight of him, of whom Moses spake in an obscure, covert manner.
*More commentary available at chapter level.