Do not go on postponing Sadaqah till you find yourself on the death-bed, with little or no hope of survival, at which
juncture, you may begin to give away your wealth saying, ‘So much to so-and-so and so much for such and such
cause, though it now belongs to your heirs. (Durre Manthur). When the hope for life vanishes, feeling for personal
needs is no longer there and, with the apprehension of all the property going to your heirs, you begin to distribute it
among Masjids and Madrasahs!
So long as the feeling of one’s own neediness was uppermost, the will to give as Sadaqah was absent. Therefore
the ‘Shariah’ has ordered that such last-moment directions for giving things in Sadaqah or to non-heirs should be
limited to a maximum of one third of the total property. Thus if the total property has been given away at the time of death, only one third of it can be validly disposed off according to such a ‘will’ of the deceased. The above Ayat specifically emphasizes spending on the orphans and the destitute while Zakaat has been mentioned separately, at the end of the Ayat.
(Taken from Fazail e Amaal Volume 2 Book of charity)