Musnad Ahmad 937:22

Ibrahim ibn Abi al-Abbas narrated to us, Baqiyyah narrated to us, he said: And Buhayr ibn Sa’d informed me, from Khalid ibn Ma’dan, he said: Abu Dharr said: Indeed, the Messenger of Allah (peace and blessings of Allah be upon him) said: "He has succeeded whose heart Allah has purified for faith, and who has made his heart sound, his tongue truthful, his soul tranquil, and his nature upright. And he has made his ear a listener, and his eye a seer. As for the ear, it is a funnel, and the eye is a confirmer of what the heart contains. And he has succeeded who has made his heart a container."