Date: 1816
From: Rabbi Moshe Sofer
To: Unknown recipient
The Chasam Sofer rules that a permanent charitable fund established in a deathbed will cannot be enforced against the heirs when the estate is insolvent, as the unspecified recipients create insurmountable bereirah problems, the shechiv mera gift mechanism fails, and the neder had no assets to attach to at the time it would have taken effect. As a compromise, he recommends the heirs voluntarily encumber the house for a modest sum sufficient to fund three scholars studying on the yahrzeit.
Source: Shu"t Chasam Sofer CM §120