And he said unto him, If thy presence go not Moses accepts what is accorded to him, whilst at the same time he signifies that it would be better and more desirable for him to perish in the desert than to go any further without the manifest token of God's presence; and this he confirms in the following verse, and therefore I have inserted the expletive particle certe (indeed,) although the copula might also be resolved into the causal particle nam (for.) For he declares that the paternal favor wherewith God had embraced the people could not be known unless He should remain with them. They are mistaken who suppose that something different is here indicated from what was said just before, for exactly in the same sense God is said to go before, and to dwell in the midst of His people; but Moses refers to the promise already given, the symbol of which was the Tabernacle of the Covenant, which just before had been removed from its proper place to punish the people's sin. What he adds at the end of the verse, "and we shall be separated," may also be resolved, "that thus we may be separated," or, "because in this way we shall be separated." Whence it is abundantly clear that the favor which is mentioned refers to their election or gratuitous adoption, and is its fruit or effect. For it was the intention of Moses to restore the Covenant which had been violated by the people to its original force, as if the people were reinstated in that honorable condition from whence they had fallen. And surely this is our real happiness after all, to be separated from heathen nations as God's own property; as it is said in Psalm 106:4, "Remember me, O Lord, with the favor that thou bearest unto thy people: O visit me with thy salvation."

If thy presence go not - אם אין פניך הלכים im ein paneycha holechim, if thy faces do not go - if we have not manifestations of thy peculiar providence and grace, carry us not up hence. Without supernatural assistance, and a most particular providence, he knew that it would be impossible either to govern such a people, or support them in the desert; and therefore he wishes to be well assured on this head, that he may lead them up with confidence, and be able to give them the most explicit assurances of support and protection. But by what means should these manifestations take place? This question seems to be answered by the Prophet Isaiah, Isaiah 63:9 : In all their affliction he was afflicted, and the Angel of his presence (פניו panaiv, of his faces) saved them. So we find that the goodness and mercy of God were to be manifested by the Angel of the Covenant, the Lord Jesus, the Messiah; and this is the interpretation which the Jews themselves give of this place. Can any person lead men to the typical Canaan, who is not himself influenced and directed by the Lord? And of what use are all the means of grace, if not crowned with the presence and blessing of the God of Israel? It is on this ground that Jesus Christ hath said, Where two or three are gathered together in my name, I am in the midst of them, Matthew 18:20; without which, what would preachings, prayers, and even Sacraments avail?

And he said unto him,.... Moses said unto the Lord:
if thy presence go not with me; or with us, as it may be as well supplied, and which agrees with what follows:
carry us not up hence; from the mount to the land of Canaan; though God had promised his presence, which was the thing requested, Moses could not forbear expressing himself after this manner, to show the high esteem he had of this blessing, and how worthless and insignificant everything else was without it; that even Canaan, the land of rest promised, was nothing in comparison of it: it is not much matter where we are, or what we have, if God is not with us; but if he grants his presence, the greatest hardships in a wilderness are made easy, and difficulties are got through with pleasure; though some read the words in the preceding verse by way of interrogation, "should my face" or "presence go", and "should it give thee rest" (z)? as carrying in it a kind of denial, which makes Moses here more urgent for it, and such a version those words seem to require.
(z) "An facies mea iret et quietem daret tibi?" Noldius, p. 243. so Junius & Tremellius, Piscator.

And he said, If thy presence go not with me, carry us not up hence - He speaks as one that dreaded the thought of going forward without God's presence.