Al-Hasan (rahimahullaah) narrated that a Faqeeh repeated a lesson in his house so many times, so an old woman of his household said to him: “By Allaah I have memorized it.” He said (to her): “Repeat it”; so she repeated it. After some days had passed, he said (to her): ”O old woman! Repeat that lesson”; so she said: “I have not memorized it.” He said: ”I repeat (or revise the lesson) lest what has afflicted you afflicts me.”
[Quoted by Shaikh Raslaan in Fadlul Ilm page: 398.
Original Source Al-Hath-thu Alaa Hifz Al-Ilm of Ibn Jawzi. page. 35]