28 Then he sent Judah before him to Joseph, to point out before him the way to Goshen. And they came to the land of Goshen.
29 So Joseph made ready his chariot and went up to Goshen to meet his father Israel; and he presented himself to him, and fell on his neck and wept on his neck a good while.
30 And Israel said to Joseph, “Now let me die, since I have seen your face, because you are still alive.”
31 Then Joseph said to his brothers and to his father’s household, “I will go up and tell Pharaoh, and say to him, ‘My brothers and those of my father’s house, who were in the land of Canaan, have come to me.
32 And the men are shepherds, for their occupation has been to feed livestock; and they have brought their flocks, their herds, and all that they have.’
33 So it shall be, when Pharaoh calls you and says, ‘What is your occupation?’
34 that you shall say, ‘Your servants’ occupation has been with livestock from our youth even till now, both we and also our fathers,’ that you may dwell in the land of Goshen; for every shepherd is an abomination to the Egyptians.”
As the Israelites approached Egypt, they knew they would be stopping in Goshen, according to Joseph’s instructions (Genesis 45:10), whereas Joseph’s headquarters were located farther south and west. Therefore Jacob sent Judah (now fully recognized as the leader among Jacob’s sons) on ahead to tell Joseph to meet them in Goshen, and to direct them exactly where to go.
As soon as he heard his father was coming, Joseph hitched up his chariot and went to Goshen to meet him. When they finally met, for the first time in over twenty-two years, the joy was almost unbearable. — Morris, pages 634-635.
The Egyptian people, according to both the Bible and secular history, despised the profession of sheepherding. Up to this point, apparently, Pharaoh had not been appraised of the fact that the Israelites kept flocks and herds. For this reason, it would be better for them to keep more or less segregated from the Egyptians.
Joseph instructed his brothers to stress this aspect of their activities to Pharaoh, as he also would himself, in order to encourage him to designate Goshen as their home. Otherwise, there might be many—perhaps even Pharoah himself—who would prefer to see the Israelites mix with the Egyptians, the better to encourage intermarriage and eventual assimilation. — Morris, page 635.
Finally, to ensure a minimum of social contact with (and hence potential molestation by) the Egyptians, Joseph instructs his family to stress (not to lie about) their role as shepherds, since every shepherd is loathsome to the Egyptians). — Wechsler, page 260.