Confuting the Views of the Qadariya

Imām al-Ridā, peace be on him, confuted the views of the fatalists (Qadariya) and disproved their vague errors during a conversation with Yūnus b. ‘Abd al-Rahmān. He, peace be on him, said: “O Yūnus, do not utter the worlds of the fatalists(Qadariya), since they do not say what the dwellers of the Garden say; nor do they say the words of the people of the Fire; nor do they say the words of Satan. The dwellers of the Garden say: Praise belongs to Allah who guided us to this; had Allah not guided us, we had surely never been guided. The people of the Fire say: Our Lord, our adversity overcame us; we were erring people. And Iblis (Satan) says: My Lord, for Your preventing me (I shall deck all affair to them in the earth).”
Yūnus denied that he would utter their words, saying: “By Allah, I do not say their words, but I say: ‘Nothing happens (in this universe) except through which Allah desires, wills, ordains, and decrees.’”
The Imām answered him, saying: “O Yūnus, it is not like that. Nothing happens except according to Allah’s desire, will, ordination, and decree. O Yūnus, do you know what Divine will (mashi’a) is?”
“No,” Yūnus replied.
The Imām explained to him the reality of Divine desire, saying: “It is the first knowledge (i.e., the prior knowledge of Allah with respect to His action). Do you know what Divine will (irāda) is?”
“No,” Yūnus answered.
The Imām explained to him the essence of Divine will, saying “It is Allah’s determination of what He wills. Do you know what fate is?”
“No,” Yunus replied.
So the Imām declared: “It is the measuring and estimating of things and the fixing of their limitations regarding their beginning and end. As for (Allah’s) decree, it means finalizing things and bringing them into (existence in) sentient world.”
Yūnus bowed in admiration and magnification for the Imām, then he kissed his head and said to him: “You have disclosed to me what I was in ignorance of. ( Usūl al-Kāfi, vol. 1, pp. 157)

Reference :The life of Imām'Ali Bin Mūsā al-Ridā