323.There are three who have a right to help from Allah: the slave whose master has agreed to his buying his freedom when he wishes to pay the sum, and the one who fights in the cause of Allah.
(Ahmad, Nisai, Tirmidhi, Ibn Majah, Hakim).
(The Lawful and Prohibited in Islam (arb: Al Halal Wal Haram Fil Islam) by. Yusuf Qaradawi).