"Uthman issued the following directive to the defense forces: "Keep in mind that you are to guard the frontiers of the Muslim dominions. You are to protect the life and property of the Muslims. I am aware of the laws that Umar formulated for your guidance. Indeed such laws were made with my consultation and the consultation of other Muslims. Be wary that I do not receive any complaint that you are violating or thwarting such laws. If you do so, God will place other persons in your stead. I am under obligation to protect your rights and privileges, but you should always weigh how far you deserve such rights and privileges.
"When a person dies, his works end, except for three: ongoing charity, knowledge that is benefited from, and a righteous child who prays for him."
Prophet Mohammed (PBUH)
"The best of what a man leaves behind are three: a righteous child who supplicates for him, ongoing charity the reward of which reaches him, and knowledge that is acted upon after him."
Sunan Ibn Mājah
"Every day two angels come down from Heaven and one of them says, 'O Allah! Compensate every person who spends in Your Cause,' and the other (angel) says, 'O Allah! Destroy every miser.'"
Sahih Bukhari