أُعِيذُكُمَا بِكَلِمَاتِ اللَّهِ التَّامَّةِ مِنْ كُلِّ شَيْطَانٍ وَهَامَّةٍ وَمِنْ كُلِّ عَيْنٍ لَامَّةٍ
Transliteration
U'idhukuma bikalimatillahit-tammati min kulli shaytanin wa hammatin wa min kulli 'aynin lammah
English meaning
I seek refuge for you both in the perfect words of Allah from every devil, every harmful creature, and every envious eye.
When is it recited?
Recited upon one's children.
Its virtue
Prophet Ibrahim (AS) used to seek protection for Ismail and Ishaq, and the Prophet (PBUH) did the same for Hasan and Husayn.
Source
Bukhari, Anbiya 10, 3371