I would differentiate between someone who is homeless, even an out and out bum, and someone who is simply a parasite. Maybe for whatever reason all a bum can do is beg, and if honest about it, then that is fair. I will give what I have. This goes back to ancient times, and I think the Old Testament mentions leaving a tenth of the product of a field for those who need it, suggesting ancient roots to charity.
Parasites, aka mooches, tend to pretend to be a friend. In some cases they will act like they are doing you a favor by their behavior.
The late Realtor Bob was a parasite, but he was an entertaining one. The occasional free meal bought his amusing digressions. Maybe that was not so much parasitism after all, as a trade of sorts. For all that, if he pushed his luck too much, he got the steak that looked a little off and had been dropped on the floor. Shrug.
I have not smoked store bought cigarettes socially since college when Chesterfields were $1.69 a pack. A fine smoke, I still miss. But few people could stand a full length unfiltered cigarette, those who could I was happy enough to let have one.
I don't recall anyone ever asking me for a bowl of pipe tobacco. I suppose if they did, I would share, the nominal cost being out weighed but getting an opinion on my blend.