Charles Ellicott Commentary Exodus 6:13

"And Jehovah spake unto Moses and unto Aaron, and gave them a charge unto the children of Israel, and unto Pharaoh king of Egypt, to bring the children of Israel out of the land of Egypt." — Exodus 6:13 (ASV)

The Lord ... gave them a charge. —The reluctance and opposition of Moses led to an express "charge" being laid upon him and Aaron, the details of which are given in Exodus 7:1-9. Exodus 6:1 of Exodus 7:1 probably originally followed Exodus 6:12 of this chapter. When the genealogy was inserted at this point, the present verse, which summarises Exodus 7:1-9, was added, as was Exodus 6:28-30 at the end of the chapter.