This and the following verses belong to the next chapter. They mark distinctly the beginning of a subdivision of the narrative.

And it came to pass - Here the seventh chapter should commence, as there is a complete ending of the sixth with Exodus 6:27, and the Exodus 6:30 of this chapter is intimately connected with the 1st verse of the succeeding.
The principal subjects in this chapter have been so amply considered in the notes, that little of importance remains to be done. On the nature of a covenant (See Clarke's note on Exodus 6:4). ample information may be obtained by referring to Genesis 6:18, and Genesis 15:9-18, which places the reader will do well to consult.
Supposing Moses to have really labored under some defect in speech, we may consider it as wisely designed to be a sort of counterbalance to his other excellences: at least this is an ordinary procedure of Divine Providence; personal accomplishments are counterbalanced by mental defects, and mental imperfections often by personal accomplishments. Thus the head cannot say to the foot, I have no need of thee. And God does all this in great wisdom, to hide pride from man, and that no flesh may glory in his presence. To be contented with our formation, endowments, and external circumstances, requires not only much submission to the providence of God, but also much of the mind of Christ. On the other hand, should we feel vanity because of some personal or mental accomplishment, we have only to take a view of our whole to find sufficient cause of humiliation; and after all, the meek and gentle spirit only is, in the sight of God, of great price.

And it came to pass on the day when the Lord spake unto Moses in the land of Egypt. This verse depends upon the following for the sense of it, which shows what it was the Lord said to Moses in the day he spake to him in Egypt, when he was come thither, which is as follows:

In Exodus 6:28-30 the thread of the history, which was broken off at Exodus 6:12, is again resumed. דּבּר בּיום, on the day, i.e., at the time, when God spake. יום is the construct state before an entire clause, which is governed by it without a relative particle, as in Leviticus 7:35; 1-Samuel 25:15 (vid., Ewald, 286i).