Question: What is the difference between Qadaa and Qadr?
Answer: “The Scholars differed in the difference between them. From them is the one who said: Qadr is Allah’s decree in eternity and Qadaa is the ruling of Allah on something when it occurs. If Allah decrees that something specific will occur in its time, then this is qadr. If the time for this thing comes then this is Qadaa. This is [found] a lot in the Noble Quran. For example, Allah’s statement:
Thus is the case judged [12:41]
And His statement:
والله يقضي بالحق
And Allah judges with truth [40:20]
And what resembles that. so Qadr is the decree of Allah in eternity and Qada is when it occurs. Some say the meaning is the same. The stronger opinion is that there is a difference between them as preceded. If one of the two word is mentioned alone, then it has one meaning and Allah knows best”.
[Majmoo’ al-Fatawa wa-Rasaail (2/79)]
Faisal Ibn Abdul Qaadir Ibn Hassan