Its obligatory on the student of knowledge to refrain from disobedience, for indeed disobedience kills the heart and weakens the understanding and its narrated about Imaam Shaafi'ee he said: "I complained to my teacher Wa'kee about my weak memory so he directed me to leave of sin and then he said, `know!!!! That knowledge is light; and the light of Allaah He does not give it to a disobedient person." And I say the proof for that is found in the Book of Allaah when He Glorified be He Says, O you who believe! If you obey and Fear Allaah, He will grant you Furqaan (a criterion), and will expiate for you your sins, and forgive you, and Allaah is the Owner of Great Bounty. [Soorah Al-Anfaal (8):29]O you who believe Fear Allaah, and believe too in His Messenger (Sallallaahu `alayhe wa Sallam), he will give you a double portion of His Mercy, and he will give you a light by which you shall walk (straight), and he will forgive you. And Allaah is Oft-Forgiving, Most Merciful. [Soorah Al Hadeed (57):28] So what is important is that the student of knowledge needs consistent striving, striving against himself and against ones passions and lower desires and its greed, and to tire himself out in acquiring knowledge, and to hope that Allaah will enable him to achieve that, and the tawfeeq (success) is from Allaah. Taken from the Book: al-Fataawaa al-Jaliyyah 'an al-Manaahij ad-Da'wiyyah pg. 111 by al-'Allaamah Ahmad bin Yahyaa an-Najamee (hafidhahullaahu ta'aalaa