Advice to one of his sons after returning from the Battle of Siffin

what does not concern you. Keep off track from which you fear to go astray because refraining (from moving) when fear of straying is better than embarking on dangers. Ask others to do good; you will thus be among good doers. Desist others from evil with your action as well as speech and keep off, to the best of your ability, from he who commits it. Struggle for Allah as is His due; and the insults of a reviler should not stop you in matters of Allah. Leap into dangers for the sake of right wherever it be. Acquire insight into religious law. Accustom yourself to endure hardships since the best trait of character is endurance in matters of right. In all affairs resign yourself to Allah, because you will thus be resigning yourself to a secure shelter and a strong protector. You should ask only from your Lord because in His hand is all the giving and depriving. Seek good (from Allah) as much as you can. Understand my advice an do not turn away from it, because the best saying is that which benefits. Know that there is no good in that knowledge which does not benefit, and if knowledge is not made use of then its acquisition is not justified. O my child, when I noticed I was of goodly age and noticed I was increasing in weakness I hastened with my will for you and wrote down prominent points of it in case death overtook before I divulged to you what I have in my heart, or in case my wit be affected as my body has been affected, or forces of passions or mischief of the world overtake you making you like a stubborn camel. Certainly, the heart of a young man is like uncultivated land. It accepts whatever is strewn on it. So, I hastened to mould you properly before your heart hardened up and your mind became occupied, so you might be ready to accept through your intelligence the results of the experience of others and be saved from going through these experiences yourself. In this way, you would avoid the hardship of seeking them and the difficulties of experimenting. Thus, you are getting to know what we had experienced and even those things are becoming clear to you which we might have missed. O my child, even though I have not reached the age which those before me have, yet I looked into their behaviour and thought over events of their lives. I walked among their ruins till I was as one of them. In fact, by virtue of those of their affairs that have become known to me it is as though I have lived with them from the first to the last. I have therefore been able to discern the impure from the clean and the benefit from the harm. I have selected for you the choicest of those matters and collected for you their good points and have kept away from you their useless points. Since I feel for your affairs as a living father should feel and I aim at giving you training, I thought it should be at a time when you are advancing in age and ne