Sahih Muslim Book - 2, Hadith - 667

و حَدَّثَنِيهِ حَرْمَلَةُ بْنُ يَحْيَى أَخْبَرَنَا ابْنُ وَهْبٍ أَخْبَرَنِي يُونُسُ بْنُ يَزِيدَ أَنَّ ابْنَ شِهَابٍ أَخْبَرَهُ قَالَ أَخْبَرَنِي عُبَيْدُ اللَّهِ بْنُ عَبْدِ اللَّهِ بْنِ عُتْبَةَ بْنِ مَسْعُودٍ أَنَّ أُمَّ قَيْسٍ بِنْتَ مِحْصَنٍ وَكَانَتْ مِنْ الْمُهَاجِرَاتِ الْأُوَلِ اللَّاتِي بَايَعْنَ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ وَهِيَ أُخْتُ عُكَّاشَةَ بْنِ مِحْصَنٍ أَحَدُ بَنِي أَسَدِ بْنِ خُزَيْمَةَ قَالَ أَخْبَرَتْنِي أَنَّهَا أَتَتْ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ بِابْنٍ لَهَا لَمْ يَبْلُغْ أَنْ يَأْكُلَ الطَّعَامَ قَالَ عُبَيْدُ اللَّهِ أَخْبَرَتْنِي أَنَّ ابْنَهَا ذَاكَ بَالَ فِي حَجْرِ رَسُولِ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ فَدَعَا رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ بِمَاءٍ فَنَضَحَهُ عَلَى ثَوْبِهِ وَلَمْ يَغْسِلْهُ غَسْلًا.

'Ubaidullah bin 'Abdullah bin 'Utbah bin Mas'ud narrated that Umm Qais bint Mihsan - who was one of the earliest Muhajir (emigrant) women who had pledged allegiance to the Messenger of Allah (s.a.w), and was the sister of 'Ukashah bin Mihsan, one of Banu Asad bin Khuzaimah - told him that she brought a son of her's, who has not yet reached the age of eating regular food, to the Messenger of Allah (s.a.w). 'Ubaidullah said: "She told me that that son of her's urinated in the lap of the Messenger of Allah (s.a.w) and the Messenger of Allah (s.a.w) called for some water which he sprinkled on his garment, and he did not wash it thoroughly."