Shabbat Ki-Teitzei 5778

The Torah demands of us that we be generous. Does it expect us to extend our generosity to the point where it becomes detrimental, both to the giver and the recipient?
Consider this hypothetical situation: you are walking on Broadway, and you encounter a person who is clearly stricken with both poverty and drug addiction. She has a handwritten sign on a cardboard box: “I need money for my heroin habit. Hey, at least I’m honest. But people are supposed to give charity, so can you spare some change?”
How about this scenario: the philanthropic leadership of American Jewry decides that it is crucial to strengthen the next generation’s Jewish identities. So they pledge to provide a free trip to Israel to any college student who has never been on an organized teen tour. As a result, families who previously planned to send their teens on USY Israel Pilgrimage decide to wait to take advantage of the free trip a few years later. As a result of severely declining enrollment, USY and other youth organizations cancel their summer Israel programs.
Is there a common thread linking these two cases? 
This week’s Torah portion, Ki Teitzei, has more commandments than any other parshah. Two in particular relate to our question. One is “If you see your fellow’s ox or sheep gone astray, do not ignore it; you must take it back to your fellow” (Deuteronomy 22:1). The other, three verses later, says, “If you see your fellow’s ass or ox fallen on the road, do not ignore it; you must help him raise it” (22:4). The common phrase, translated as “do not ignore it,” is interesting in the original Hebrew–Vehit’alamta meihem.” Notice that the Hebrew doesn’t include the word lo, so there’s nothing explicitly negative in the phrase. It doesn’t actually say “don’t.” Could that mean that there are circumstances where need should be ignored?
We’ll look at this question through rabbinic lenses on Shabbat morning.
Wishing you a Shabbat Shalom,
Rabbi David Wise