"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 (Using translation from Nasāʾī 2761)  

أَقَامَ رَسُولُ اللهِ ﷺ تِسْعَ سِنِينَ لَمْ يَحُجَّ ثُمَّ أَذَّنَ فِي النَّاسِ بِالْحَجِّ فَلَمْ يُبْقِ أَحَدٌ يَقْدِرُ عَلَى أَنْ يَأْتِيَ رَاكِبًا أَوْ رَاجِلًا إِلَّا قَدِمَ فَتَدَارَكَ النَّاسُ لِيَخْرُجُوا مَعَهُ حَتَّى جَاءَ ذَا الْحُلَيْفَةِ وَوَلَدَتْ أَسْمَاءُ بِنْتُ عُمَيْسٍ مُحَمَّدَ بْنَ أَبِي بَكْرٍ فَأَرْسَلَتْ إِلَى رَسُولِ اللهِ ﷺ فَقَالَ «اغْتَسِلِي وَاسْتَثْفِرِي بِثَوْبٍ ثُمَّ أَهِلِّي» فَفَعَلَتْ