Imam explains the matter as following:
While you are in the seminary, along with your studies, you should refine yourselves, so that when you leave the seminary and become the leader of a people in a city or district, they may profit from you, take advice from you, and reform themselves by means of your deeds and manners and your ethical virtues.
Try to reform and refine yourselves before you enter among the people. If now, while you are unencumbered, you do not reform yourselves, on the day when people come before you, you will not be able to reform yourselves.
Many things ruin people and keep them from studying and purifying themselves, and one of them, for some, is this very beard and turban! When the turban becomes a bit large, and the beard gets long, if one has not refined oneself, this can hinder one’s studies, and restrict one. It is difficult to trample the commanding self under one’s feet, and to sit at the feet of another for lessons.
Shaykh at-Tusi, may Allah have mercy on him, at the age of fifty-two would go to classes, while between the ages of twenty and thirty, he wrote some of his books! His Tahdhib was possibly written during this period. Yet at the age of fifty-two he attended the classes of the late Sayyid Murtada, may Allah have mercy on him, and thereby achieved a similar status as he did.
God forbid that prior to acquiring good habits and strengthening one’s spiritual powers that one’s beard should turn a bit white and that his turban should get big, so that he would lose the blessings of knowledge and spirituality. So work, before your beards before white; before you gain the attention of the people, think about your state!
God forbid that before a person develops himself, that people should pay heed to him, that he should become a personality and have influence among the people, causing him to loose his soul. Before you loose hold of the reins of your self, develop and reform yourself! Adorn yourselves with good traits, and remove your vices! Become pure in your lessons and discussions, so that you may approach God!