Musnad Ahmad 27:1755

Sulayman ibn Dawud al-Hashimi narrated to us, Sa'id ibn 'Abd al-Rahman informed us, from 'Ubayd Allah, from Nafi', from Ibn 'Umar, that the Prophet (peace and blessings of Allah be upon him) said: "The righteous vision is one part of seventy parts of prophethood. So whoever sees good, let him praise Allah for it and mention it. And whoever sees other than that, let him seek refuge in Allah from the evil of his vision, and let him not mention it, for it will not harm him."