Hadith 706
وَحَدَّثَنِي عَنْ مَالِكٍ، عَنْ يَحْيَى بْنِ سَعِيدٍ، عَنْ سَعِيدِ بْنِ الْمُسَيَّبِ، أَنَّ أَسْمَاءَ بِنْتَ عُمَيْسٍ، وَلَدَتْ، مُحَمَّدَ بْنَ أَبِي بَكْرٍ بِذِي الْحُلَيْفَةِ فَأَمَرَهَا أَبُو بَكْرٍ أَنْ تَغْتَسِلَ، ثُمَّ تُهِلَّ .
Yahya related to me from Malik from Yahya ibn Said from Said ibn al-Musayyab that Asma bint Umays gave birth to Muhammad ibn Abi Bakr at Dhu'l-Hulayfa and Abu Bakr told her to do ghusl and then enter ihram
Sahih Lighairihi (Salim al-Hilali)
Muwatta Malik 706 · Book 20, Hadith 2