This prayer was an intercession, not only for the sons of Jacob, but also for their descendants--that God would deliver the Ten Tribes in time to come, as He delivered the two, Judah and Benjamin, and after He permitted the destruction of two Temples, He would grant endless continuance to the third.
Jacob also put a letter addressed to the viceroy of Egypt into the hands of his son. The letter ran thus: "From thy servant Jacob, the son of Isaac, the grandson of Abraham, prince of God, to the mighty and wise king Zaphenathpaneah, the ruler of Egypt, peace! I make known unto my lord the king that the famine is sore with us in the land of Canaan, and I have therefore sent my sons unto thee, to buy us a little food, that we may live, and not die. My children surrounded me, and begged for something to eat, but, alas, I am very old, and I cannot see with mine eyes, for they are heavy with the weight of years, and also on account of my never-ceasing tears for my son Joseph, who hath been taken from me. I charged my sons not to pass through the gate all together at the same time, when they arrived in the city of Egypt, in consideration of the inhabitants of the land, that they might not take undue notice of them. Also I bade them go up and down in the land of Egypt and seek my son Joseph, mayhap they would find him there.