Bismillah
as salam alykom
Dan I m not sure if I did answer your question, however, coming back home today I thought u might have been looking for more explanation.
Well to do so thru my humble knowledge.
The Messenger salla Allah a`lyhee wa sallam is saying here that one who fasts the whole month of Ramadan due to the belief of the importance of fasting and in obedience to Allah Who Ordrained it in addition to devoting the fast sincerely to Allah, shall be rewarded with the elimination of his/her sins committed during the past year.
While observing the night of Qdar using the recommended means for this, including prayer, reciting Quran all night. Just this one night will also result into the same rewared. Thus, a Muslim who is advantaged of performing both shall gain the double reward.
Hope I helped.... any input.
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