Ramban on Genesis 47:4/רמב"ן על בראשית מ״ז:ד׳

1TO SOJOURN IN THE LAND ARE WE COME; FOR THERE IS NO PASTURE FOR THY SERVANTS’ FLOCKS. I wonder about this reason which they told to Pharaoh, for there was also no pasture in Egypt; the famine was as severe in the land of Egypt as it was in the land of Canaan, or even more so, for it was against Egypt that the main decree was directed. Perhaps they said that in the land of Canaan, due to the severity of the famine, people were eating the grass of the field and were not leaving any sustenance for the cattle. However, in the land of Egypt where there is corn, people subsist on that, and thus in Egypt there is a little pasture left. It is possible that in the land of Egypt there was a little pasture in the reedgrass on account of the rivers and the ponds.