When intending to copulate with one’s wife, recite this Dua. If he has children then Shaytaan will not be able to overpower them and will not be able to harm them. (Bukhari vol.2 pg.776)
بِسْمِ اللهِ اَللّٰهُمَّ جَنِّبْنَا الشَّيْطَانَ وَجَنِّبِ الشَّيْطَانَ مَا رَزَقْتَنَا
I commence this act in the name of Allah, O Allah, protect us from Shaytaan and keep Shaytaan away from that child that You will grant us.
- Beautiful Sunnats