Various testimonies are available with regard to the intellectual accomplishments of Imam (a.s) in form of statements of Moayyad, Imam Zuhri, Saeed bin Musayyab, Ibn Jazm, Sufyan bin Uyanna and Abu Hamzah Thumali etc. who are called the best of Tabeins (companions of companions) and who were great scholars of their time. They used to express pride on their discipleship of Imam Zainul Abideen (a.s). They used to say, "When the springs of knowledge burst from the tongue of Imam (a.s) it seemed as if waves of precious stones were gushing out. Our mental capacities proved ineffective in preserving the sayings of Imam (a.s)."