In his book The Caliphate, its Rise, Decline and Fall, Sir William Muir has paid his tribute to Ali in the following words; "In the character of Ali, there are many things to commend. Mild and beneficent, he treated Basra when prostrate at his feet with a generous forbearance. Towards theocratic fanatics, who wearied his patience by incessant intrigues and insensate rebellion, he showed no vindictiveness. Excepting Muawiyah, the man of all others whom he ought not to have estranged, be carried the policy of conciliating his enemies to a dangerous extreme. In compromise indeed and in procrastination lay the failure of his caliphate. With greater vigor, spirit, and determination, he might have averted the schism which for a time threatened the existence of Islam, and which has never ceased to weaken it. Ali was wise in counsel and many an adage sapient proverbs have been attributed to him. But like Solomon, his wisdom was for others than for himself.
"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