What is the power of a blessing? Before he died, Jacob blessed his grandsons Menashe and Ephraim but gave more prominence to the younger grandson Ephraim. Some verses later we are told: Joseph saw the third generation of sons from Ephraim, and the sons, as well, of Machir son of Menashe were born on Joseph’s knees. In other words, great-grandchildren were already born to the younger Ephraim, while Menashe was seeing grandchildren. The Torah tells us this, explains the Malbim, to show us the power of a blessing.