Oppose the oppressor and support the oppressed.
Oppose the oppressor and support the oppressed. I advise you, and all my children, my relatives, and whosoever receive this message, to be conscious of Allah, to remove your differences, and to strengthen your ties. I heard your grandfather, peace be upon him, say: “Reconciliation of your differences is more worthy than all prayers and all fasting.” Fear Allah in matters concerning orphans. Attend to their nutrition and do not forget their interests in the middle of yours.
My first and foremost advice to you, my son, is to fear Allah. Be His obedient servant. Keep His thought always fresh in your mind. Be attached to and carefully guard the principles (Islam) which connect you with Him. Can any other connection be stronger, more durable and more lasting than this to command greater respect and consideration or replace it? Accept good exhortations and refresh your mind with them. Adopt piety and kill your inordinate desires with its help.
Build your character with the help of true faith in religion and Allah. Subjugate your nature with the vision of death, make it see the mortality of life and of all that it holds dear, force it to realize the actuality of misfortunes and adversities, the changes of circumstances and times and compel it to study the lives of past people. Persuade it to see the ruined cities, the dilapidated palaces, decaying signs and relics of fallen empires of past nations.
Then meditate over the activities of those people, what they have all done when they were alive and were in power, what they achieved, from where they started their careers; where, when and how they were brought to an end, where they are now; what have they actually gained out of life and what was their contributions to the human welfare.
If you carefully ponder over these problems, you will find that each one of those people has parted company with the others and with all that he cherished and loved and he is now in a solitary abode, alone and unattended; and you also will be like him. Take care to provide well for your future abode. Do not barter away eternal blessings for the pleasures of this mortal and fleeting world. Do not talk about things which you do not know.
Do not speculate about and pass verdicts on subjects about which you are not in a position to form an opinion and are not called upon to do so. Give up the way where there is a possibility of your going astray.