Hadith
حَدَّثَنَا عَبْدُ اللَّهِ بْنُ مَسْلَمَةَ، عَنْ مَالِكٍ، عَنْ أَبِي النَّضْرِ، عَنْ سُلَيْمَانَ بْنِ يَسَارٍ، عَنِ الْمِقْدَادِ بْنِ الأَسْوَدِ، أَنَّ عَلِيَّ بْنَ أَبِي طَالِبٍ، - رضى الله عنه - أَمَرَهُ أَنْ يَسْأَلَ لَهُ رَسُولَ اللَّهِ صلى الله عليه وسلم عَنِ الرَّجُلِ إِذَا دَنَا مِنْ أَهْلِهِ فَخَرَجَ مِنْهُ الْمَذْىُ مَاذَا عَلَيْهِ فَإِنَّ عِنْدِي ابْنَتَهُ وَأَنَا أَسْتَحْيِي أَنْ أَسْأَلَهُ . قَالَ الْمِقْدَادُ فَسَأَلْتُ رَسُولَ اللَّهِ صلى الله عليه وسلم عَنْ ذَلِكَ فَقَالَ " إِذَا وَجَدَ أَحَدُكُمْ ذَلِكَ فَلْيَنْضَحْ فَرْجَهُ وَلْيَتَوَضَّأْ وُضُوءَهُ لِلصَّلاَةِ " .
Narrated Al-Miqdad ibn al-Aswad: Ali ibn AbuTalib commanded him to ask the Messenger of Allah (ﷺ) what a man should do when he wants to have intercourse with his wife and the prostatic fluid comes out (at this moment). (He said): I am ashamed of consulting him because of the position of his daughter. Al-Miqdad said: I asked the Messenger of Allah (ﷺ) about it. He said: When any of you finds, he should wash his private part, and perform ablution as he does for prayer
Sahih · Al-Albani
Sunan Abi Dawud 207 ·Book 1, Hadith 207·Also available on sunnah.com·