Sahih Muslim 287c
Ubaidullah b. Abdullah b. 'Utba b. Mas'ud said:
Umm Qais, daughter of Mihsan, was among the earliest female emigrants who took the oath of allegiance to the Messenger of Allah (ﷺ), and she was the sister of 'Ukkasha b. Mihsan, one amongst the sons of Asad b. Khuzaima. He (the narrator) said: She (Umm Qais) told me that she came to the Messenger of Allah (may peace he upon him) with her son and he had not attained the age of eating food. He (the narrator, 'Ubaidullah), said: She told me that her son passed urine in the lap of the Messenger of Allah (ﷺ). The Messenger of Allah (ﷺ) sent for water and sprayed it over his garment (over that part which was contaminated with the urine of the child) and he did not wash it thoroughly.
وَحَدَّثَنِيهِ 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 أَمَّ قَيْسٍ بِنْتَ مِحْصَنٍ، - وَكَانَتْ مِنَ الْمُهَاجِرَاتِ الأُوَلِ اللاَّتِي بَايَعْنَ رَسُولَ اللَّهِ صلى الله عليه وسلم وَهِيَ أُخْتُ عُكَّاشَةَ بْنِ مِحْصَنٍ أَحَدُ بَنِي أَسَدِ بْنِ خُزَيْمَةَ - قَالَ أَخْبَرَتْنِي أَنَّهَا أَتَتْ رَسُولَ اللَّهِ صلى الله عليه وسلم بِابْنٍ لَهَا لَمْ يَبْلُغْ أَنْ يَأْكُلَ الطَّعَامَ - قَالَ عُبَيْدُ اللَّهِ - أَخْبَرَتْنِي أَنَّ ابْنَهَا ذَاكَ بَالَ فِي حِجْرِ رَسُولِ اللَّهِ صلى الله عليه وسلم فَدَعَا رَسُولُ اللَّهِ صلى الله عليه وسلم بِمَاءٍ فَنَضَحَهُ عَلَى ثَوْبِهِ وَلَمْ يَغْسِلْهُ غَسْلاً ‏.‏