[Machine] The Prophet ﷺ used to wash the part of his garment that was affected by semen, then he would go out to pray and I would look at the trace of the stain on his garment in the area of washing.  

النَّبِيَّ ﷺ كَانَ إِذَا أَصَابَ ثَوْبَهُ الْمَنِيُّ غَسَلَ مَا أَصَابَ مِنْهُ ثَوْبَهُ ثُمَّ خَرَجَ إِلَى الصَّلَاةِ وَأَنَا أَنْظُرُ إِلَى أَثَرِ الْبُقَعِ فِي ثَوْبِهِ ذَلِكَ فِي مَوْضِعُ الْغُسْلِ  

[Machine] I used to wash it from the clothes of the Messenger of Allah ﷺ , then he would go out to pray while the traces of washing were still visible as water stains on his clothes.  

كُنْتُ أَغْسِلُهُ مِنْ ثَوْبِ رَسُولِ اللهِ ﷺ فَيَخْرُجُ إِلَى الصَّلَاةِ وَأَثَرُ الْغُسْلِ فِي ثَوْبِهِ بُقْعُ الْمَاءِ  

[Machine] The Prophet ﷺ used to wash his semen and then go out for prayer in that garment, and I would see the traces of the washing on it. This narration was narrated by Muslim from Abu Bakr ibn Abi Shaybah, and likewise...  

النَّبِيَّ ﷺ كَانَ يَغْسِلُ الْمَنِيَّ ثُمَّ يَخْرُجُ إِلَى الصَّلَاةِ فِي ذَلِكَ الثَّوْبِ وَأَنَا أَنْظُرُ إِلَى أَثَرِ الْغُسْلِ فِيهِ وَرَوَاهُ مُسْلِمٌ عَنْ أَبِي بَكْرِ بْنِ أَبِي شَيْبَةَ وَكَذَلِكَ