(66) باب مَا يَقُولُ الرَّجُلُ إِذَا أَتَى أَهْلَهُ
Narrated Ibn `Abbas:
The Prophet (ﷺ) said, "If anyone of you, when having sexual intercourse with his wife, says: Bismillah, Allahumma jannibni-Sh-Shaitan wa jannib-ish-Shaitan ma razaqtana, and if it is destined that they should have a child, then Satan will never be able to harm him."
Reference: Sahih al-Bukhari 5165
In-book reference: Book 67, Hadith 100
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 7, Book 62, Hadith 94