Moses is very concerned about Pharaoh and his bad attitude toward the Hebrews. God lets him know that Pharaoh will basically be driving the Hebrews out when He is done with him.
God reaffirms his promise, the same promise He made to Abraham, to Isaac, and to Jacob. He lets Moses know that the Hebrews will be returning to Canaan. God tells them that He is with them, that He will be their God and they his people. In truth, once we know God (which we cannot do unless we truly know love), that is all we need. The Hebrews chafe under Pharaoh’s rule and their bondage, and they have forgotten the value of their God.
God tells Moses to go take care of this mess and talk again to Pharaoh. Moses basically wonders how on earth this is supposed to work. From Matthew Henry’s commentary:
“The faith of Moses was so feeble that he could scarcely be kept to his work. Ready obedience is always according to the strength of our faith. Though our weaknesses ought to humble us, yet they ought not to discourage us from doing our best in any service we have to do for God. When Moses repeats his baffled arguments, he is argued with no longer, but God gives him and Aaron a charge, both to the children of Israel, and to Pharaoh.”¹
God issues his command once again in Exodus 6:13, and declines to discuss the point further.
After this, we are treated to a genealogical aside, after which the narrative is resumed, with the scripture showing the Lord issuing His command.
¹ Henry, Matthew. http://www.christnotes.org/commentary.php?com=mhc&b=2&c=6