The giving of gifts is discussed in AN8.33
A person might give a gift out of favoritism or hostility or stupidity or cowardice. Or they give thinking, ‘Giving was practiced by my father and my father’s father. It would not be right for me to abandon this family tradition.’ Or they give thinking, ‘After I’ve given this gift, when my body breaks up, after death, I’ll be reborn in a good place, a heavenly realm.’ Or they give thinking, ‘When giving this gift my mind becomes clear, and I become happy and joyful.’ Or they give a gift thinking, ‘This is an adornment and requisite for the mind.’
Rather than focus on the poisoned outcomes of ways of giving, it might be simplest to simply focus on the best way to give a gift. Specifically, the giving of alms is
an adornment and requisite for the mind
If we conduct all our giving in this manner, then the problem of giving gifts unpoisoned is solved.
However, there is also the matter of receiving gifts that were given with unwholesome (e.g., poisened) intent. From AN4.78:
And how is a religious donation purified by the recipient, not the giver?
It’s when the giver is unethical, of bad character, but the recipient is ethical, of good character.
This is quite significant, because the recipient receives the gift as given, without resentment and with full acceptance.