Al-Matalib al-'Aliyah 3020 — hadiths 3020–3021

It is narrated that Abdullah bin Abd al-Rahman bin Abi Husayn said: It has reached me that Luqman the Wise used to say: "O my dear son, do not acquire knowledge in order to vaunt your superiority over the scholars and boast before them, nor to quarrel and argue with the foolish, nor to show off and make a display in gatherings; and do not abandon acquiring knowledge out of disinclination toward it or out of a liking for ignorance. O my dear son, when you see people remembering Allah Almighty, sit with them, for if you are learned, your knowledge will benefit you, and if you are ignorant, they will teach you; and it is greatly hoped that Allah Almighty will look upon them with His mercy, and that mercy will reach you too in their company."
Imam Ahmad bin Hanbal (may Allah have mercy on him) recorded it in his book al-Zuhd.