The First Visit of the Brothers to Egypt to Buy Corn (Genesis 42:1-38).
‘Now Jacob saw that there was corn in Egypt, and Jacob said to his sons, “Why do you look one on another?” And he said, “Behold, I have heard that there is corn in Egypt. Get yourselves down there and buy for us from there, that we might live and not die.” And Joseph's ten brothers went down to buy corn from Egypt, but Jacob did not send Benjamin, Joseph's brother, with his brothers, for he said “In case mischief befalls him.” '
At this stage, of course, they did not know that there were years of famine to come. But things were clearly bad. The rain had not come and their stores of corn were getting low and there was little prospect of renewing it locally, for everyone was suffering in the same way. But then came the news that Egypt had a sufficiency of corn and was willing to sell it to foreigners.
Through the centuries Egypt, with its usually unfailing water source in the Nile, was famed for its agricultural prosperity, and would regularly welcome Canaanites who would come in times of famine, and they would provide for them in return for reward. They were regularly welcomed into the areas across the borders, where they were allowed to stay until the situation improved and they could return to their own place. On one ancient grave relief ‘Asiatics who did not know from what they would live' are depicted as bowing before the general Haremhab (c1330 BC).
So he had no hesitation in sending his sons to buy corn there. But he refused to let Benjamin go because he still remembered what had (in his own mind) happened to Joseph.