Genesis 50:23

Joseph saw Ephraim’s children. It is not certain whether Ephraim’s great-grandchildren or his grandchildren are meant. In the second commandment of the Decalogue the expression “third and fourth generation” (Ex. 20:5; Deut. 5:9) apparently includes the fathers, and means the grandchildren and great-grandchildren. It is used in the same sense in Num. 14:18. However, in Ex. 34:7, where the following sequence is given, fathers, children, children’s children, third and fourth generation, the latter two generations obviously refer to great-grandchildren and great-great-grandchildren. Since sometimes the father is included in the number of generations mentioned, and sometimes excluded, it is uncertain, in Joseph’s case, what was meant. At the same time it is perfectly clear that Moses desired to show that Joseph lived to see the beginning of the fulfillment of his father’s blessing. There is no practical difficulty in Joseph’s seeing the great-grandsons of Ephraim. Since his 2 sons were born before he himself was 37 years old (ch. 41:50), he may have had grandsons by the time he was 56 or 60, and great-grandsons 20 years later at the age of 80. Great-grandsons may thus have been born when he was approximately 100 years old.

The children also of Machir. In the case of Manasseh’s children Moses is more definite, stating specifically that Joseph saw his own great-grandchildren.

Upon Joseph’s knees. Literally, “were born upon Joseph’s knees” (see on ch. 30:3).