Musannaf Ibn Abi Shayba 33:359

Narrated to us Abd al-Wahhab al-Thaqafi, from Ayyub, from Abu Qilabah, from Abu al-Darda’, who said: You will not attain all of understanding (fiqh) until you despise people for the sake of Allah, then you return to your own self and be even more despising of it.