He asked his sister Umm Habibah, the wife of the Prophet: "Did the Messenger of Allah ever offered prayer in a garment in which he had sexual intercourse?" She said: "Yes, if there was nothing noxious on it."  

أَنَّهُ سَأَلَ أُخْتَهُ أُمَّ حَبِيبَةَ زَوْجَ النَّبِيِّ ﷺ هَلْ كَانَ رَسُولُ اللَّهِ ﷺ يُصَلِّي فِي الثَّوْبِ الَّذِي يُجَامِعُ فِيهِ قَالَتْ نَعَمْ إِذَا لَمْ يَكُنْ فِيهِ أَذًى  

"The Messenger of Allah came out to us with water dripping from his head, and he led us in prayer wearing a single garment, placing its one end on the right shoulder, and the other end on the other shoulder. When he finished praying, 'Umar bin Khattab said to him: 'O Messenger of Allah, did you lead us in prayer wearing a single garment? He said: 'Yes, I perform prayer in it, and in it I (i.e. I had sexual intercourse in it)."  

خَرَجَ عَلَيْنَا رَسُولُ اللَّهِ ﷺ وَرَأْسُهُ يَقْطُرُ مَاءً فَصَلَّى بِنَا فِي ثَوْبٍ وَاحِدٍ مُتَوَشِّحًا بِهِ قَدْ خَالَفَ بَيْنَ طَرَفَيْهِ فَلَمَّا انْصَرَفَ قَالَ عُمَرُ بْنُ الْخَطَّابِ يَا رَسُولَ اللَّهِ تُصَلِّي بِنَا فِي ثَوْبٍ وَاحِدٍ قَالَ نَعَمْ أُصَلِّي فِيهِ وَفِيهِ أَىْ قَدْ جَامَعْتُ فِيهِ  

"A man asked the Prophet whether he could perform prayer in a garment in which he had intercourse with his wife. He said: 'Yes, unless he sees something on it, in which case he should wash it.'"  

سَأَلَ رَجُلٌ النَّبِيَّ ﷺ يُصَلِّي فِي الثَّوْبِ الَّذِي يَأْتِي فِيهِ أَهْلَهُ قَالَ نَعَمْ إِلاَّ أَنْ يَرَى فِيهِ شَيْئًا فَيَغْسِلَهُ