Think a little of the conditions of Ali ibn al-Hussein, the supplications of that great man and his implorings to Allah, the Exalted as well as his elegant invocations, by which he taught the disciplines of servitude to the servants of Allah. I do not allege that the supplications of those great men were intended to teach how to worship, for it would be an empty and meaningless statement prompted by being ignorant of the state of Lordship and of the knowledge of Ahl al-Bayt. Their fear and awe were much greater than anybody else's, and the Greatness and Majesty of Allah were manifested in their hearts more than in anyone else's heart. I only say that the servants of Allah should learn from them how to worship Allah and how to travel to Him. When you read what they used to say in their supplications and invocations, you should not read them as mere pronunciations of the tongue. They should be pondered upon, and their behavior with Allah, their displaying humility, inefficiency and destitution, are also to be noted.
By the Beloved! Ali ibn al-Hussein was one of the greatest blessings which Allah, the Most High, had bestowed upon His servants as a grace, bringing him down from the sacred world of Proximity, for the sake of teaching the ways of servitude to His servants:" Then, on that Day, you shall most certainly be questioned about the bliss. "If we are asked:" Why did you not appreciate the value of that bliss and did not get benefit from that great man?," we shall have no reply but to droop down our heads for being ashamed, and to be burnt with the fire of remorse and regret, when no regret would avail.
Source: Disciplines of the prayer, Page: 522