Umar r.a made his daughter the CEO of the endowment (waqf) properties after he dies

It is reported in Abu Dawud that ‘Umar رضي الله عنه wrote,


In the name of Allah, the Compassionate, the Merciful. This is what Allah’s servant ‘Umar, Commander of Faithful, directed in case some incident happens to him (i.e. he dies), that Thamg, Sirmah bin al-Akwa’, the servant who is there, the hundred shares in (the land of) Khaibar, the servant who is there and the hundred shares which Muhammad (ﷺ) had donated to me in the valley (nearly) will remain in the custody of Hafsah during her life, then the men of (knowledge/good) opinion from her family will be in charge of these (endowments), that these will neither be sold nor purchased, spending (its produce) where they think (necessary on the beggar, deprived and relatives). There is no harm to the one in charge (of this endowment) if he eats himself, or feeds, or buys slaves with it. [Saheeh Abu Dawoud #2879]

What is Waqf? Its condition? Read here: https://enlightcenterq8.wordpress.com/2017/05/01/the-status-of-endowment-waqf-in-islam/