Answer
(Fatwa: 1732/1393/B=1433)
In the question mentioned above, his statement about the construction of a mosque is a will which will be executed in one third property. If he has no wealth except this amount then as per his will one third amount shall be taken away for the construction of the mosque and the remaining amount shall be divided into 10 shares; out of which 2-2 shares shall go to the brothers and 1-1 share to the sisters.
Allah (Subhana Wa Ta’ala) knows Best
Darul Ifta,
Darul Uloom Deoband