If one declares his wish to found an endowment

As Umar رضي الله عنه founded an endowment and said that it was not sinful for its administrator to eat from its yield, but he did not specify whether he (i.e., Umar) or someone else would be its administrator. The Prophet (ﷺ) ﷺ said to Abu Talha, "I recommend that you should divide it (i.e., the garden) among your relatives." So Abu Talha agreed and distributed it among his relatives and his cousins.