And they shall know that I am the LORD their God, that brought them forth out of the land of Egypt, that I may dwell among them: I am the LORD their God. And they shall know that I am the Lord their God - That is, They shall acknowledge God, and their infinite obligations to him. In a multitude of places in Scripture the word know should be thus understood.
That I may dwell among them - For without this acknowledgment and consequent dependence on and gratitude and obedience to God, they could not expect him to dwell among them.
By dwelling among the people God shows that he would be a continual resident in their houses and in their hearts; that he would be their God - the sole object of their religious worship, to whom they should turn and on whom they should trust in all difficulties and distresses; and that he would be to them all that the Creator could be to his creatures. That in consequence they should have a full conviction of his presence and blessing, and a consciousness that He was their God, and that they were his people. Thus then God dwells among men that they may know him; and they must know him that he may continue to dwell among them. He who does not experimentally know God, cannot have him as an indwelling Savior; and he who does not continue to know - to acknowledge, love, and obey him, cannot retain him as his Preserver and Sanctifier. From the beginning of the world, the salvation of the souls of men necessarily implied the indwelling influences of God. Reader, hast thou this salvation? This alone will support thee in all thy travels in this wilderness, comfort thee in death, and give thee boldness in the day of judgment. "He," says an old writer, "who has pardon may look his judge in the face."
Commentary on the Bible, by Adam Clarke [1831].