Imam Malik's Muwatta, Chapter: The Evil Eye

Yahya related to me from Malik that Humayd ibn Qays al-Makki said, "A man came to the Messenger of Allah, may Allah bless him and grant him peace, with the two sons of Jafar ibn Abi Talib. He said to their nursemaid, 'Why do I see them so thin?' Their nursemaid said, 'Messenger of Allah, the evil eye goes quickly to them. Nothing stops us from asking someone to make incantations (using ayats of Quraan) for them, except that we do not know what of that would agree with you.' The Messenger of ,Allah, may Allah bless him and grant him peace, said, 'Make incantations for them. Had anything been able to precede the decree, the evil eye would precede it.' "