From a letter to an Umawi Caliph by Al-Hasan of Basra (d. 110H) from Abdul-Malik ibn Marwan to Al-Hasan ibn Abi'l-Hasan al-Basri
Peace be to you, and I extol you to Allah, beside whom there is nothing worthy of worship.
As for what follows, there has come to the Commander of the Believers about you that concerning the description of al-qadr (Divine Decree) the likes of which have never come to him from any of the past.
The Commander of the Believers cannot remember any of the Companions of the Prophet whom he knew saying what it had come to him that you have said. He has always known good things of you in your ways, your excellence in religion and knowledge of religious insight (fiqh) and your search and your eagerness for that.
And then the Commander of Believers found repugnant this doctrine ascribed to you; therefore write to him about your doctrine and the position you take - whether it is a tradition from the Companions of Allah's Messenger, on whom be peace and Allah's blessing, or only an opinion of yours, or something you know how to prove from the Qur'an. For truly, we have heard no one discuss this matter before you. Present your opinion to the Commander of Believers and clarify it.
Peace be to you, and the Mercy of Allah and His blessings.
In reply from Al-Hasan al-Basri to Allah's servant Abdul-Malik
Peace be on you, O Commander of the Believers, and the mercy of Allah. I extol you to Allah, beside whom there is nothing worthy of worship. As for what follows, may Allah bless the Commander of the Believers, may He place him among His friends who do works of obedience and desire His good pleasure and hasten to follow what He has commanded.
Those among the Companions who accomplished Allah's command, related His wisdom and followed the tradition of His messenger, on whom be peace and Allah's blessing, never denied a truth or justified a wrong or attached to the Lord anything He did not attach to himself. Allah has said:
"I have not created the Jinn and mankind except to serve Me: I desire no sustenance from them, neither do I desire food to be fed."
Now Allah would not create them for something and then come between them and it - He is no oppressor of His servants. None of those who went before denied that, or even discussed it, because they were in agreement about it.
We ourselves only began to talk about it when people began to deny it following their misleading desires and committing grave sin: distorting the Book of Allah. What Allah forbade is not from Him, because He is not pleased with what He is angry about, and not angry with what He is pleased about, and if infidelity (kufr) were by Allah's decree or ordaining, then it would please Him from whomever it came. It is inconceivable that He would decree something and then be displeased with His own decree. Allah would not openly forbid His servants something, and then covertly decree it for them, as stupid ignorant men say. Were that the case, He would not have said:
"Let him who wills believe and him who wills disbelieve."
That is because Allah has placed in them the power (al-qudra) by which they go forward or lag behind, so that the doer of good may merit Paradise and the doer of bad may merit the Fire. If the matter were as falsifiers have interpreted it, it would not be in them to go ahead of remain behind, and there would be no praise for him who went forward or blame for him who lagged. According to what they say, power does not come from them and should not be attributed to them, rather, it is a thing that works by means of them. They follow what is ambiguous in the Qur'an seeking dissension.
They argue that Allah, the Exalted, has said:
"Allah leads astray whomsoever He will, and guides to Him all those who repent"
And they do not look at what comes before it and after it. If they did they would not go astray.
Know, Commander of the Believers, that those who differ from Allah's commands and Book and justice are those who transgress in the matter of their religion, and who in their ignorance transfer responsibility to divine decree (al-qadr). If you order any of them concerning the matter of his religion, he says, 'The pen has run dry, and it is written on our foreheads whether we shall be happy or miserable (in this world and the next)'. But if you said to one of them, 'Do not weary yourself seeking the world, or go out in the morning in the heat and cold, and endanger your life on a journey, for your sustenance is decided about that', then he would find fault with you.
Their idea is that Allah has charged His servants to take what they have no power to take, and to leave what they have no power to leave, but Allah, the Exalted, gives them the lie with His Word:
"Allah imposes on no soul beyond its capacity."
No, surely Allah has known that infidelity will come from them just as it happens by their own choice. Know, Commander of the Believers, that Allah did not foreordain matters for His servants, but He said, 'If you do such and such, I will do such and such, and if you do thus and so, I will do thus and so'.
Speak to yourself, Commander of the Believers. Do not say, 'Allah has foreordained for His servants what He forbade them, and come between them and what He ordered them to do, and sent the prophets to call them to the opposite of what He has decreed for them, so as to torment them everlastingly if they did not do what He did not let them do'. Allah is exalted far above what wrongdoers claim! This is the answer to what you asked me about, I have explained it and clarified it. Reflect on it and ponder it, for it is a cure for what is in the heart.