Authentic Supplication Number 147.

The Messenger of Allah  used to solicit protection for Al-Hasan and Al-Hussein, may Allah be pleased with them [saying]: ‘U`eethukuma bikalimatil-lahi ‘at-tammati min kulli shaytanin wa hammatin, wa min kulli `eynin lammatin (166) and he would say: Your forefather (speaking to the two) used to solicit protection for Isma`eel and Ishaq with this supplication.

(166) I solicit the protection of the two of you in the perfect, and complete Words of Allah from every shaytan and venomous reptile, and from every evil eye.

Reported by Al-Bukhari. Al-Albani included this hadeeth in The Authentic of Good Sayings as #118.