Is it permissible for a brother who has received money for jihad to take from it to secure housing for himself and his wife, who is participating in jihad, and for another brother who is with him working in jihad, and to manage their family affairs, after his home was destroyed?

If a person is given money for a specific purpose, he is an agent and is not permitted to dispose of it except in the manner for which he was appointed. He is not permitted to spend these funds for his own benefit, nor for the benefit of his wife or his brother. He can inform the entrusting party of his need. If they grant him permission, then that is good and excellent. Otherwise, he must seek another means to provide housing for himself and his brother.