Muhammad al-Baqir
Fifth Twelver Sh?‘ah Im?m, grandson of Husayn, and second generation grandson of Muhammad.
Fasting is a shield against (hell) fire. Charity and dole remove and finish sin, as does the remembrance of God in the midnight.
There is no servant except that there exists a white spot upon his heart. So when he commits a sin, a black spot arises into that white spot. Then when he repents, this black spot moves away. But if he continues on committing sins, the blackness of this spot increases till such time that it overwhelms and overrides the whiteness. When the whiteness is all covered over (by the blackness), the owner of it (the heart) does never at all return towards beneficence and goodness. And This is what God means when he says: "Nay! rather, what they used to do has become like a rust upon their hearts." (Qur'an, 83:14)
Indeed, faithful is the one who - when pleased and glad, his pleasure does not make him enter into sin and falsehood; and when unhappy and angry, his anger does not oust him from the world of righteousness; and when he gains power, his power does not make him commit excess, nor opression, nor make him go for a thing upon which he does not have any right.
The parable of a man greedy of this world is the parable of the silk worm: the more it winds the thread round itself the farther it becomes from salvation, until it dies of grief.
Knowledge and science is the fruit of paradise; in times of threat it is one's ally, in exile it keeps one company, and in solitude it is one's intimate friend and companion.