Sahih al-Bukhari 231
Sahih al-Bukhari · Book 4: Ablutions (Wudu') · If the (traces of) Janaba (semen) or other spots are not removed completely on washing
Narrated `Amr bin Maimun:
حَدَّثَنَا مُوسَى ، قَالَ حَدَّثَنَا عَبْدُ الْوَاحِدِ ، قَالَ حَدَّثَنَا عَمْرُو بْنُ مَيْمُونٍ ، قَالَ سَأَلْتُ سُلَيْمَانَ بْنَ يَسَارٍ فِي الثَّوْبِ تُصِيبُهُ الْجَنَابَةُ قَالَ قَالَتْ عَائِشَةُ كُنْتُ أَغْسِلُهُ مِنْ ثَوْبِ رَسُولِ اللَّهِ صلى الله عليه وسلم، ثُمَّ يَخْرُجُ إِلَى الصَّلاَةِ وَأَثَرُ الْغَسْلِ فِيهِ بُقَعُ الْمَاءِ.
I heard Sulaiman bin Yasar talking about the clothes soiled with semen. He said that `Aisha had said, "I used to wash it off the clothes of Allah's Messenger (ﷺ) and he would go for the prayers while water spots were still visible on them.