Musannaf Ibn Abi Shayba 33:1024

Al-Fadl ibn Dukayn narrated to us, he said: Zuhayr narrated to us, from Muhammad ibn Suqah, from Abu Ja’far, he said: There was not one among the companions of the Messenger of Allah (may Allah bless him and grant him peace) who, when he heard a hadith from the Messenger of Allah (may Allah bless him and grant him peace), was more cautious—neither adding to it nor subtracting from it—than Abdullah ibn Umar.