gave zakaah when not entitled to it

My brother has a mental disability and some people gave us zakaah
forhim. Please note that my brother is not in need andhe has his own
income which reaches the nisaab, and zakaah is paid on it. What should
we do with this money that came to us? Do we have the right to dispose
of it and give itto someone who is entitled to it?.
Praise be to Allaah.
If your brother is independent of means or has someone who spends on
him, then he is not entitled to zakaah and it is not permissible for
you to accept any money that comes that you know is zakaah. You have
to tell the one who is giving zakaah that your brother is not entitled
to it, because the Prophet (blessings and peace of Allah be upon him)
said concerning zakaah: "No one who is independent of means or who is
strongand able to earn a living should have any share in it." Narrated
by Abu Dawood, 1391 and al-Nasaa'i, 2551; classed as saheeh by
al-Albaani inSaheeh Sunan Abi Dawood.
And he (blessings and peace of Allah be upon him) said: "Charity is
not permissible for a rich person, or for one who is strong and
healthy." Narrated by Abu Dawood, 1329; al-Tirmidhi, 589; al-Nasaa'i,
2550; Ibn Maajah, 1829. Classed as saheeh by al-Albaani in Saheeh
Sunan al-Nasaa'i.
Whatever you have of thismoney must be given back to the one who
gaveit, so that he can give it tosomeone who is entitled to it. But if
he delegates you to give it to people who are entitled to zakaah,
there is nothing wrong with that.
It says in Mataalib Ooli al-Nuha (2/259): If zakaahis given to someone
who is not entitled to it, because the giver was unaware of that, the
one who took it has to return it to him with any increase in it,
whether in weight or in the form of offspring [as in the case ofa
donated sheep, camel, etc], because it is in increase in the giver's
wealth.

And Allah knows best.