Musnad Ahmad 31:21

Rab'i ibn Ibrahim narrated to us, Abd al-Rahman ibn Ishaq narrated to us, from Abd al-Rahman ibn Mu'awiyah, from al-Harith, the freed slave of Ibn Siba', from Abu Sa'id al-Khudri: That the Messenger of Allah (peace and blessings of Allah be upon him) said: "Whoever seeks self-sufficiency, Allah will make him self-sufficient, and whoever seeks to be chaste, Allah will make him chaste."