daf bit: Ketuvot 68

After discussing the importance of giving charity even when one questions the need, our rabbis taught: if a man pretends to have a blind eye, a swollen belly, or a humped back, he will not pass from the world without being so afflicted. If a man accepts charity but does not need it, he will not leave the world without coming to need it. (68a)

Presumably this concerns willful, deceitful acts, not misjudgements. If everyone believes in both the obligation to give charity and the obligation to not accept it if you don't really need it, you could end up with some pretty bad cases of "no, I insist" / "no, I can't". So I read this as a call for honest self-examination, not one to accept charity only as a matter of life or death.