Obligation of fulfilling the will as it is if it is in the best interests of the legatee

Q: I had a sister that was called Shar`a' bint `Ajab, she died about 13 years ago. Since I was present at her death, she bequeathed that I shall make a public fountain and plant a palm tree for her from her money. After she died, the legacy was divided into three parts: two parts (Part No. 16; Page No. 349) for the heirs and the third one remained with me, and since then, I have been developing her bequest, and making a lot of charity works for her, such as providing drinking water for people, buying dried dates from the palms and giving them away to the poor, donating five hundred, one or two thousands of her money to contribute to establishing any newly constructed Masjid (mosque) in the neighborhood, besides buying water motors and taps and putting them at the places of watering, so that people can benefit from them, and now, I still have around twenty thousands left of the bequest. I have asked some shaykhs about this, and they have told me to fulfill her bequest by making a public fountain and planting a palm tree. I hope that you would advise me on what I have done, and what to do regarding the bequest, as I am the one in charge of it. May Allah reward you with the best.

A: The administrator of the bequest should execute the will of the legator, which is to make a public fountain and to plant a palm tree, as long as it involves a clear benefit for people living in the town. May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.