What does 'God buries his servants, but never his program' mean?
It means God's servants are mortal and will die and be buried, but His divine program never stops. Great men of God come and go, yet God's plan keeps moving forward. Joseph died and was placed in a coffin in Egypt, but God's promise to visit Israel and bring them out continued.
Les teaches this at the close of Genesis. Joseph lived 110 years, saw Ephraim's children and Manasseh's descendants, and then told his brethren he was dying. He assured them God would surely visit them and bring them out of Egypt to the land sworn to Abraham, Isaac, and Jacob. Joseph took an oath that they would carry his bones back to Canaan. He died, was embalmed, and put in a coffin in Egypt. Genesis begins with "in the beginning God created" but ends with a coffin, death. Yet the point is that God buries His servants—great men of God come and go—but His program just keeps moving on. Les notes he read the statement from several authors but does not know who originally said it. The context then moves into Exodus.