Genesis 43:2

And it came to pass, when they had eaten up the corn which they had brought out of Egypt,.... Which, in so numerous a family as Jacob's was, having so many children, grandchildren, and servants, what nine men on so many asses could bring with them must be consumed in a short time, how long cannot be said; no doubt they lived sparingly on it in such a time of scarcity, to make it last as long as they could, and perhaps only he, his children and grandchildren, might eat of it; the servants, as Calvin observes, might live on meaner food, as acorns, herbs, and roots; and it must not be thought that all this corn was eaten up entirely, and none left, but the far greater part of it, and but very little remaining; or otherwise, how should Jacob, and his sons' wives and children be supported until the return of his sons from Egypt with fresh provisions? indeed it may be supposed, that the land of Canaan produced some corn, though but little; and it is certain there were other fruits which were serviceable for food, as appears from Genesis 43:11:

their father said, go again, buy us a little food; just enough for him, and them, and theirs, for the present; hoping that the famine would be over quickly, and therefore orders them to go once more to Egypt, and buy some provisions: they made no motion themselves to go, as it is highly probable they determined they would not, since Jacob had resolved Benjamin should not go, but waited for their father's motion, and which he did not make until necessity obliged him.