If the donor does not specify the amount of the waqf, what should be done?
Question

If the person who is setting up a waqf says, “Take from this waqf and feed the poor” and he dies without having specified the amount of food, what should the supervisor do?.
Praise be to Allah.We put this question to Shaykh ‘Abd al-Rahmaan ibn Jibreen (may Allaah preserve him), who answered as follows: 
He should look at what is customary (al-‘urf) and at the usage of the word ta’mah (feeding the poor) in those days. What was usually meant by it was to offer iftaar and dinner to fasting people, even if it was only three or five poor persons who were in need of iftaar after fasting. 
And Allaah knows best.