I'm going to change my mind about giving my food to a homeless man
Why would you not want to give a homeless man your food?
Thankfully, I was already done with my food, but I don't know if it's right to give something you eat to a homeless man
You should continue helping the homeless since it's the right thing to do. You heart is in the right place but you need to consider if you might pass some kind of bacteria onto them because you had ate some of the food.
I didn't pass food to the homeless man so there's nothing to worry about.
I think you did the right thing by not giving him the food you had already partially eaten. It would be a nice gesture though to instead buy a meal for the homeless man. I'm sure he would appreciate that!