Shaykh Muhammad ibn Saalih al Uthaymeen stated:
I encourage you likewise such that the effect of knowledge is manifested upon you and you know that the outward bearing of the student of knowledge is: dignity and acting in a patient, unhurried manner and fine manners with his companions and with other than them.
So you find the student of knowledge who has taken benefit from his knowledge will be teaching the people by means of his haal (condition) that which they benefit from, (and it is) greater than the benefit they take from his speech – meaning that (the benefit that take from) their imitating his actions and his manners is more than that which they take from his statements.
This is because the actions and the manners of the student of knowledge are a true representation of the student of knowledge.
As for (his) merely acquiring the branches of knowledge but they are not manifested upon him and it is not known “is he a student of knowledge or (just) a man in the street”? Then this (person) has nottaken any benefit from his knowledge.
(Quoted in Wasaayaa wa tawjeehaat li tullaab il ‘ilm pp142 to 143, translated by Nasser ibn Najam)