Yahya related to me from Malik from Abdullah ibn Dinar that Abdullah ibn Umar related that Umar ibn al-Khattab mentioned to the Messenger of Allah ﷺ that he would sometimes become junub in the night. The Messenger of Allah ﷺ said to him, "Do wudu and wash your penis, and then sleep."  

أَنَّهُ قَالَ ذَكَرَ عُمَرُ بْنُ الْخَطَّابِ لِرَسُولِ اللَّهِ ﷺ أَنَّهُ يُصِيبُهُ جَنَابَةٌ مِنَ اللَّيْلِ فَقَالَ لَهُ رَسُولُ اللَّهِ تَوَضَّأْ وَاغْسِلْ ذَكَرَكَ ثُمَّ نَمْ  

‘Umar b. al-Khattab said to the Messenger of Allah (May peace be upon him) that he became sexually defiled at night (asking him what he should do). The Messenger of Allah (May peace be upon him) said : You should perform ablution and wash your penis and then sleep. (Using translation from Abū Dāʾūd 221)   

حَدَّثَنَا الْقَعْنَبِيُّ عَنْ مَالِكٍ عَنْ عَبْدِ اللَّهِ بْنِ دِينَارٍ عَنِ ابْنِ عُمَرَ أَنَّهُ قَالَ ذَكَرَ عُمَرُ بْنُ الْخَطَّابِ لِرَسُولِ اللَّهِ ﷺ أَنَّهُ تُصِيبُهُ الْجَنَابَةُ مِنَ اللَّيْلِ فَقَالَ رَسُولُ اللَّهِ ﷺ «تَوَضَّأْ وَاغْسِلْ ذَكَرَكَ ثُمَّ نَمْ»  

[Machine] Umar ibn Al-Khattab narrated that he used to experience seminal emission during the night, so the Messenger of Allah ﷺ advised him, "Perform ablution and wash your private parts, then sleep."  

ذَكَرَ عُمَرُ بْنُ الْخَطَّابِ ؓ لِرَسُولِ اللهِ ﷺ أَنَّهُ تُصِيبُهُ الْجَنَابَةُ مِنَ اللَّيْلِ فَقَالَ لَهُ رَسُولُ اللهِ ﷺ تَوَضَّأْ وَاغْسِلْ ذَكَرَكَ ثُمَّ نَمْ