The Edomite, as descended from Esau the twin brother of Jacob (compare Deuteronomy 2:4), and the Egyptian, as of that nation which had for long shown hospitality to Joseph and his brethren, were not to be objects of abhorrence. The oppression of the Egyptians was perhaps regarded as the act of the Pharaohs rather than the will of the people Exodus 11:2-3; and at any rate was not to cancel the memory of preceding hospitality.
In their third generation - i. e. the great grandchildren of the Edomite or Egyptian alien: compare the similar phrase in Exodus 20:5.