Ibn ‘Abbas reported the Prophet ﷺ as saying “If anyone who means to have intercourse with his wife says “In the name of Allaah, O Allaah, keep us away from the devil and keep the devil away from what You hast provided us.” It will be ordained that no devil will ever harm the child born to them. (Using translation from Abū Dāʾūd 2161)
قَالَ رَسُولُ اللهِ ﷺ لَوْ أَنَّ أَحَدَهُمْ إِذَا أَتَى أَهْلَهُ قَالَ بِسْمِ اللهِ اللهُمَّ جَنِّبْنِي الشَّيْطَانَ وَجَنِّبِ الشَّيْطَانَ مَا رَزَقْتَنِي فَيُولَدُ بَيْنَهُمَا وَلَدٌ فَيَضُرَّهُ الشَّيْطَانُ أَبَدًا