The great scholar Sufyan ath-Thawri (may God be pleased with him) is reported to have said,
“Knowledge is three hand-spans: the first breeds arrogance, the second breeds humility, and in the third, you realize you know nothing.”
When one first embarks on religious studies, one may feel a heady sense of confidence at gaining proficiency in the Islamic sciences that may lead one to arrogance. With further study and time, however, one may begin to realize that issues that once seemed so clear-cut are actually more complex than one initially believed, and that there is great depth in matters one first perceived as shallow. This is the second “hand-span” that Sufyan ath-Thawri refers to which engenders a sense of humility in a person and reverence for others of more knowledge.
As one continues one their path of study, one may realize that no matter how deeply one delves into knowledge and how much expertise one attains, one is limited in one’s abilities, and it is only Allah subhanahu wa ta`ala (exalted is He) who has full and all-encompassing knowledge. Any number divided by the infinite is zero; in the same way, any knowledge we have attained, in comparison to Allah’s perfect and complete knowledge, is in reality nothing. Realizing one’s own deficiencies in light of Allah’s perfection and His infinite knowledge brings one’s heart to a beautiful state of intense humbleness and devotion. This is the third “hand-span” and the state in which one has truly internalized what Allah (swt) says in the Qur’an in Surah Yusuf:
(نَرْفَعُ دَرَجَاتٍ مِّن نَّشَاء وَفَوْقَ كُلِّ ذِي عِلْمٍ عَلِيمٌ)
“We raise in degrees (of knowledge) whom We will, but over every possessor of knowledge is One [more] Knowing.” (12:76)