Later, when the water had to be turned to blood in the first of the ten plagues, Moses could not be involved. It wouldn’t be fair for him, even indirectly, to bring suffering upon the waters that had done him a good turn.
There is a lesson to be learned from this episode – gratitude. One should not repay good with evil: “Don’t bite the hand that feeds you.”
It’s a good rule, but what happens if the person you show gratitude to didn’t really mean to do you a favour?
Take the case of the Egyptians. The Torah commands us, “Do not hate an Egyptian, for you were a stranger in his land” (Deut. 23:8).
“A stranger in his land”? When the Egyptians were treating us so harshly and we were downtrodden slaves in their midst? What were we – their pampered guests? Are we meant to say, “Thank you, Egyptians, for making our lives hell?”
Nachmanides, on the verse in D’varim we have quoted, says that the Torah meant what it said.
There were things about the Egyptians which we can never forgive and forget… but there were also (admittedly) minor things which in the end brought us at least a modicum of benefit.
According to Nachmanides, in time of severe famine – which must have destroyed many other peoples – the Israelites survived because they were in Egypt where they did not go hungry, even though it was poor-men’s bread that they ate.