Abu Dhakwan narrated to us. He said: I heard Ibrahim b. al-`Abbas say: I have never seen al-Rida (as) asked about anything except that he knew its answer. I have never seen one more knowledgeable than him since his time and age. Al-Ma’mun would test him by asking him about everything, and he would answer him. His words, his answers, and his metaphors were all from the verses of the Quran. He would complete [reciting] it every three days, and he would say: Had I wanted to finish it in fewer than three days, I would have done so. However, I do not ever pass by a verse without thinking about it, why it was revealed and when – and for that reason, I finish it every three days.