The Shaykh (rahima-hullaah) mentions:

((There is no doubt, the more a person increases in knowledge, naturally he increases in learning and differentiating the truth from the falsehood, and the harmful from the beneficial, and like this he reaches a level whereby Allaah bestows understanding upon him.

This is because taqwa is a means for strengthening understanding, and strong understanding assists in increasing knowledge.

So you see two men memorising an aayah from the Book of Allaah, one of them can extract from it three rulings, whilst the other is able to extract more than this, according to that which Allaah has blessed him with in understanding.))

Shaykh Ibn 'Uthaymeen

Kitaabul-'Ilm

Ref: Fatwa-Online

Shaykh Abdur-Razzaaq al-`Abbaad said:

"So the point being that these Forty (Hadeeth of Imaam an-Nawawi) are indeed very great, and it is befitting upon every muslim that he (likewise) offers them great care and attention, (how?)"

Ref: The Importance of Imaam an-Nawawi's Forty Hadeeth