Praise be to Allaah.
A brother is obliged to spend on his sister if she is poor
and he is independent of means and he would inherit from her if she died. If
he would not inherit from her because she has a son or because the father or
grandfather (father's father) is still alive, then he is not obliged to
spend on her and it is permissible to give her the zakaah of his wealth in
Ibn Qudaamah (may Allaah have mercy on him) said in
In order for maintenance to be obligatory, three conditions
must be met:
They should be poor and have no
wealth or source of income which would make them independent of being
maintained by others. If they have enough wealth or income to make them
independent of means, then it is not obligatory to spend on their
The one who is obliged to spend
on their maintenance should have enough to do so, surplus to the costs of
his own maintenance, either from his wealth or his income. If he does not
have any surplus, then he is not obliged to do anything, because of the
report of Jaabir that the Messenger of Allaah (blessings and peace of Allaah
be upon him) said: “If one of you is poor, then let him start with himself.
If he has any surplus, then let him spend on his dependents, and if he has
any surplus, let him spend on his relatives.”
The one who spends should be an
heir, because Allaah says (interpretation of the meaning): “And on the
(father’s) heir is incumbent the like of that (which was incumbent on the
father)” [al-Baqarah 2:233]. And because there are ties of kinship between
those who would inherit from one another which dictate that the heir is more
entitled to the wealth of the one who leaves it behind than anyone else, so
by virtue of the ties of kinship he is to be singled out for maintenance
rather than anyone else. If he is not an heir, then he is not obliged to
spend on his maintenance. End quote.
Shaykh Ibn ‘Uthaymeen said in al-Sharh al-Mumti’
The basic principle in our view is that it is essential that
the one who spends be an heir of the one on whom he spends, except for
direct ascendants and descendants, in which case the issue of inheritance is
not a condition. End quote.
Based on this, if the brother is obliged to spend on his
sister, it is not permissible to give the zakaah of his wealth to her, but
if he is not obliged to spend on her, it is permissible to give the zakaah
of his wealth to her, and indeed that is better than giving it to someone
else who is not one of his relatives, because by doing this he will attain
the reward of both zakaah and upholding the ties of kinship.
And Allaah knows best.