Earnestness, perseverance, and assiduity are indispensable in the quest for knowledge. This is indicated in the Quran, in the very words of God, the Exalted, Those who have earnestly striven in Our cause, We shall surely guide them to Our ways (29:69); and O John [Yahya], take the Book with power (19:12). It is said that he who seeks something and is industrious [in so doing] shall find it; and he who knocks at the door and is persistent shall enter. And it is said that you will reach what you desire [only] to the extent that you pursue it. It is said as well that the industriousness of three kinds of people is essential in [the pursuit of] knowledge and understanding: the student, the teacher, and the father, if he is among the living.
The most influential factors in [strengthening] memory are industriousness and commitment. Reducing one's consumption, [increasing] prayer at night, and reading the Quran are also factors for [improving] one's memory. It is said that nothing increases memory retention more than reading the Quran silently; and reading the Quran silently is most excellent, for [the Prophet] said, "The most excellent among the works of my community is the reading of the Quran silently." Al-Shaddad ibn Hakim saw one of his deceased brothers in his dream and said to him, "What thing did you find the most useful [for your Afterlife]?" He replied, "Reading the Quran silently." One should say when lifting the Quran, "In the name of God, and glory be to God, and praise be to God, and there is no God but God, and God is the greatest, and there is no power or strength except in God, the Exalted, the Mighty, who knows the number of all the letters that ever were [written] and that ever shall be written throughout the centuries and ages." And let it be said after each prescribed [prayer], "I believe in God, the One, the Unique, the Truth, who has no companion; and I do not believe in any [deity] besides Him." [One] should also pray much [that God send] blessings and peace upon the Prophet (peace be upon him), for he is a mercy for the worlds.