"The Messenger of Allah stayed for nine years during which he did not perform Hajj. Then it was announced among the people the he was going for Hajj. No one who was able to come riding or on foot stayed behind, and the people rushed to go out with him until he came to Dhul-Hulaifah. Asam' bint 'Umais gave birth to Muhammad bin Abi Bakr and she sent word to the messenger of Allah (Asking what she should do). He said: 'Perform Ghusl and wrap a cloth around your private parts, then begin the Talbiyah.' So she did that." An abridgment  

أَقَامَ رَسُولُ اللَّهِ ﷺ تِسْعَ سِنِينَ لَمْ يَحُجَّ ثُمَّ أَذَّنَ فِي النَّاسِ بِالْحَجِّ فَلَمْ يَبْقَ أَحَدٌ يَقْدِرُ أَنْ يَأْتِيَ رَاكِبًا أَوْ رَاجِلاً إِلاَّ قَدِمَ فَتَدَارَكَ النَّاسُ لِيَخْرُجُوا مَعَهُ حَتَّى جَاءَ ذَا الْحُلَيْفَةِ فَوَلَدَتْ أَسْمَاءُ بِنْتُ عُمَيْسٍ مُحَمَّدَ بْنَ أَبِي بَكْرٍ فَأَرْسَلَتْ إِلَى رَسُولِ اللَّهِ ﷺ فَقَالَ اغْتَسِلِي وَاسْتَثْفِرِي بِثَوْبٍ ثُمَّ أَهِلِّي فَفَعَلَتْ مُخْتَصَرٌ  

"Asma' bint 'Umais gave birth to Muhammad bin Abi Bakr and she sent word to the Messenger of Allah asking him what she should do. He told here to perform Ghusl and wrap her private parts in a cloth, and to begin the talbiyah.  

نَفَسَتْ أَسْمَاءُ بِنْتُ عُمَيْسٍ مُحَمَّدَ بْنَ أَبِي بَكْرٍ فَأَرْسَلَتْ إِلَى رَسُولِ اللَّهِ ﷺ تَسْأَلُهُ كَيْفَ تَفْعَلُ فَأَمَرَهَا أَنْ تَغْتَسِلَ وَتَسْتَثْفِرَ بِثَوْبِهَا وَتُهِلَّ