Musannaf Ibn Abi Shayba 33:739

Shababa ibn Sawwar narrated to us, from Layth ibn Sa’d, from Ibn ‘Ajlan, from ‘Awn, who said: It used to be said: Whoever Allah has made his form beautiful and placed him in a righteous position, then he humbled himself for the sake of Allah, he would be among the sincere ones of Allah.