Sahih Muslim Book - 16, Hadith - 3533

حَدَّثَنَا يَحْيَى بْنُ يَحْيَى وَإِسْحَاقُ بْنُ إِبْرَاهِيمَ - وَاللَّفْظُ لِيَحْيَى - قَالاَ أَخْبَرَنَا جَرِيرٌ عَنْ مَنْصُورٍ عَنْ سَالِمٍ عَنْ كُرَيْبٍ عَنِ ابْنِ عَبَّاسٍ قَالَ قَالَ رَسُولُ اللَّهِ -صلى الله عليه وسلم- « لَوْ أَنَّ أَحَدَهُمْ إِذَا أَرَادَ أَنْ يَأْتِىَ أَهْلَهُ قَالَ بِاسْمِ اللَّهِ اللَّهُمَّ جَنِّبْنَا الشَّيْطَانَ وَجَنِّبِ الشَّيْطَانَ مَا رَزَقْتَنَا فَإِنَّهُ إِنْ يُقَدَّرْ بَيْنَهُمَا وَلَدٌ فِى ذَلِكَ لَمْ يَضُرَّهُ شَيْطَانٌ أَبَدًا ».

It was narrated that Ibn 'Abbas said: "The Messenger of Allah (s.a.w) said: 'If one of you says, when he wants to have intercourse with his wife, "Bismillah, Allahumma! Jannibnash-Shaitan wa jannibish Shaitana ma razaqtana. (In the name of Allah, O Allah, keep the Shaitan away from us and keep the Shaitan away from that with which You provide us,' then if it is decreed that they should have a child from that, the Shaitan will never harm him."