Is an endowment valid if the endower conditions that he benefit from it himself and that his descendants, males only and not females, benefit from it?

Question:
A woman endowed a shop on the condition that a sacrifice be performed for her from its proceeds every year, and that the remainder of the shop’s rent go to her son’s descendants, males only and not females. Is this endowment valid, given that it has been in effect for nearly two hundred years? And how is it to be validated if it is invalid?

Answer:
This is one of the issues that past endowments faced, where they were made contingent on the responsibility of the one who endowed them. However, from the outset, we prohibit this; no one should do this from the beginning. As for something in the past that has been in effect for a hundred years, or where people’s endowments were made contingent on their own responsibility and liability, that is a different matter. Yes.