Musnad Ahmad 25:738

Muhammad ibn Ja'far narrated to us, Shu'bah narrated to us, from Mansur, from Salim ibn Abi al-Ja'd, from Kurayb, from Ibn Abbas, from the Prophet (peace and blessings of Allah be upon him), that he said: "If one of you—or if one of them—when he comes to his wife, says: 'O Allah, keep Satan away from me, and keep Satan away from what You provide for me,' then if a child is decreed between them, Satan will never be empowered over him—or Satan will never harm him."