Should a woman wash herself when she sees a sexual dream and sees (the marks) of liquid? He (the Holy Prophet) said: Yes. 'A'isha said to her: May your hand be covered with dust and injured. She narrated: The Messenger of Allah ﷺ said: Leave her alone. In what way does the child resemble her but for the fact that when the genes contributed by woman prevail upon those of man, the child resembles the maternal family, and when the genes of man prevail upon those of woman the child resembles the paternal family.  

لِرَسُولِ اللَّهِ ﷺ هَلْ تَغْتَسِلُ الْمَرْأَةُ إِذَا احْتَلَمَتْ وَأَبْصَرَتِ الْمَاءَ فَقَالَ نَعَمْ فَقَالَتْ لَهَا عَائِشَةُ تَرِبَتْ يَدَاكِ وَأُلَّتْ قَالَتْ فَقَالَ رَسُولُ اللَّهِ ﷺ دَعِيهَا وَهَلْ يَكُونُ الشَّبَهُ إِلاَّ مِنْ قِبَلِ ذَلِكِ إِذَا عَلاَ مَاؤُهَا مَاءَ الرَّجُلِ أَشْبَهَ الْوَلَدُ أَخْوَالَهُ وَإِذَا عَلاَ مَاءُ الرَّجُلِ مَاءَهَا أَشْبَهَ أَعْمَامَهُ  

Should a woman wash herself when she sees a sexual dream and sees (the marks) of liquid? He (the Holy Prophet) said: Yes. 'A'isha said to her: May your hand be covered with dust and injured. She narrated: The Messenger of Allah ﷺ said: Leave her alone. In what way does the child resemble her but for the fact that when the genes contributed by woman prevail upon those of man, the child resembles the maternal family, and when the genes of man prevail upon those of woman the child resembles the paternal family. (Using translation from Muslim 314b)   

يَا رَسُولَ اللهِ هَلْ تَغْتَسِلُ الْمَرْأَةُ إِذَا احْتَلَمَتْ أَوْ أَبْصَرْتِ الْمَاءَ؟ فَقَالَ نَعَمْ فَقَالَتْ لَهَا عَائِشَةُ تَرِبَتْ يَدَاكِ فَقَالَ رَسُولُ اللهِ ﷺ دَعِيهَا وَهَلْ يَكُونُ الشَّبَهُ إِلَّا مِنْ قِبَلِ ذَلِكَ إِذَا عَلَا مَاؤُهَا مَاءَ الرَّجُلِ أَشْبَهَ الْوَلَدُ أَخْوَالَهُ وَإِذَا عَلَا مَاءُ الرَّجُلِ مَاءَهَا أَشْبَهَ الْوَلَدُ أَعْمَامَهُ  

"دَعِيهَا، وَهَلْ يكونُ الشَّبَهُ إِلا مِن قبَلِ ذَلِكَ، إِذا عَلَا ماؤُهَا مَاءَ الرَّجُلِ أَشبه الولد أَخواله، وإِذا عَلَا ماءُ الرَّجُل ماءَها أَشْبَهَ أَعَمامَه".