Kommentar zu Bereschit 42:2

רדו שמה GO DOWN THITHER — He did not say to them לכו “Go ye” but רדו an allusion to the 210 years during which Israel was to be enslaved in Egypt corresponding to the numerical value of (רד״ו (210 (Genesis Rabbah 91:2).

ונחיה, even if we cannot buy enough food to eat to our satisfaction, at least it will be enough not to die from the famine. This is why Yaakov added the words ולא נמות, “and we will not die.”

ונחיה ולא נמות. "so that we shall live and not die." The reason that Jacob repeated "so that we shall not die," was that negligence would be a capital sin for which an accounting would have to be given even in the Hereafter. On the other hand, if they made appropriate efforts to secure a supply of food, their lives in this world as well as in the Hereafter would be assured.

This alludes to the 210 years... The correct text of Rashi omits, “He did not say לכו but rather רדו.” This is because no teaching can be derived from רדו. Scripture needs to write רדו (go down) — for Eretz Yisrael is higher than the other lands, so רדו is the right term for going from Eretz Yisrael to Egypt, as Re’m writes. And so the term ירידה is written in the entire section. Rashi is answering the question: Why does Scripture need to write, “Go down there”? It is written right afterward, “And buy for us from there.” Thus it should just say, “Go down and buy for us from there.” Perforce, it is written רדו שמה (Go down there) to allude that they will be there (שמה) for 210 (רד''ו) years. But without the word “there,” we would be unable to expound anything. Alternatively, we could say that the correct text of Rashi includes, “He did not say לכו but rather רדו,” and Rashi is answering the question: Why is it written רדו, which connotes downfall? It should use the favorable term of לכו (go). Despite Eretz Yisrael being higher than the other lands, it should not use a term which connotes downfall. Perforce, “This alludes to the 210 years...”

The verse might also be read thus: ונחיה, "so that we may live comfortably," ולא נמות "or at least not die." It would all depend on the amount they were able to buy in Egypt.