from Yazid bin Salamah Al-Ju'fi, he said: "Yazid bin Salamah 'O Messenger of Allah! I heard so many narrations from you that I am afraid the last of them will cause me to forget the first of them. So narrate a statement to me that will encompass them.' So he said: 'Have Taqwa of Allah with what you learn.'"
Jami` at-Tirmidhi Book 41, Hadith 39