The Messenger of Allah (sal Allahu alaihi wa sallam) said: “O Abu Dharr! If you learn one verse from The Book of Allah (The Quran), it is better for you than to voluntarily pray one hundred rakahs; and if you learn a category of knowledge (religion), regardless if it is applied or not, it is better for you than to voluntarily pray one thousand rakahs.” [Sunan Ibn Majah]
The reason that acquiring religious knowledge has so much superiority over praying nafl rakahs is because of the potential of much greater benefit to oneself and society as a result of knowledge of the Deen. The rules Allah (subhana wa ta’ala) has set out for mankind are for our worldly benefit, as well as for earning everlasting happiness and perfection that can only be enjoyed in the Akhirah. Even if a person does not initially translate their knowledge of right and wrong into action, the possibility exists that they may do so. On the other hand, without guidance one wanders around blindly.
We can start earning the reward of a hundred nafl rakahs daily by learning one ayat, its meaning and implications, every day. Similarly, we can hope for great reward from Allah (subhana wa ta’ala) for acquainting ourselves with ahadith, one of the two major sources of Islam.
Source: Hadith App.