Why did it state in the Quran that Allah's knowledge of the presence of sick people among Muslims, and those traveling for trade and jihad, came after the command to perform the night vigil (qiyam al-layl), as if it were newly acquired knowledge, even though His knowledge, glory be to Him, is eternal?

Allah Almighty knew from eternity the reasons that necessitate alleviation. So, He commanded what involved hardship then alleviated it and removed the burden, so that people may know His mercy and be grateful to Him. He, Glorified be He, knew the abrogating and the abrogated from eternity. Scholars have explained the wisdom of abrogation, stating that it is not due to any new knowledge that occurred to Allah, but rather for wisdoms, among them: observing the interests of His servants, gradual legislation for its perfection, and testing those who are obligated in their acceptance of transformation, their gratitude upon alleviation, and their patience upon increased burden. The statement that abrogation implies bada' (alteration of divine will) on Allah is a refuted misconception, for abrogation does not necessitate bada'.