Narrated `Urwa:

Aisha the wife of the Prophet, said, "Allah's Messenger (ﷺ) used to examine the believing women who migrated to him in accordance with this Verse: 'O Prophet! When believing women come to you to take the oath of allegiance to you... Verily! Allah is Oft-Forgiving Most Merciful.' (60.12) `Aisha said, "And if any of the believing women accepted the condition (assigned in the above-mentioned Verse), Allah's Messenger (ﷺ) would say to her. "I have accepted your pledge of allegiance." "He would only say that, for, by Allah, his hand never touched, any lady during that pledge of allegiance. He did not receive their pledge except by saying, "I have accepted your pledge of allegiance for that."

حَدَّثَنَا إِسْحَاقُ، حَدَّثَنَا يَعْقُوبُ بْنُ إِبْرَاهِيمَ، حَدَّثَنَا ابْنُ أَخِي ابْنِ شِهَابٍ، عَنْ عَمِّهِ، أَخْبَرَنِي عُرْوَةُ، أَنَّ عَائِشَةَ ـ رضى الله عنها ـ زَوْجَ النَّبِيِّ صلى الله عليه وسلم أَخْبَرَتْهُ أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم كَانَ يَمْتَحِنُ مَنْ هَاجَرَ إِلَيْهِ مِنَ الْمُؤْمِنَاتِ بِهَذِهِ الآيَةِ، بِقَوْلِ اللَّهِ ‏{‏يَا أَيُّهَا النَّبِيُّ إِذَا جَاءَكَ الْمُؤْمِنَاتُ يُبَايِعْنَكَ‏}‏ إِلَى قَوْلِهِ ‏{‏غَفُورٌ رَحِيمٌ‏}‏‏.‏ قَالَ عُرْوَةُ قَالَتْ عَائِشَةُ فَمَنْ أَقَرَّ بِهَذَا الشَّرْطِ مِنَ الْمُؤْمِنَاتِ قَالَ لَهَا رَسُولُ اللَّهِ صلى الله عليه وسلم ‏"‏ قَدْ بَايَعْتُكِ ‏"‏‏.‏ كَلاَمًا وَلاَ وَاللَّهِ مَا مَسَّتْ يَدُهُ يَدَ امْرَأَةٍ قَطُّ فِي الْمُبَايَعَةِ، مَا يُبَايِعُهُنَّ إِلاَّ بِقَوْلِهِ ‏"‏ قَدْ بَايَعْتُكِ عَلَى ذَلِكَ ‏"‏‏.‏ تَابَعَهُ يُونُسُ وَمَعْمَرٌ وَعَبْدُ الرَّحْمَنِ بْنُ إِسْحَاقَ عَنِ الزُّهْرِيِّ‏.‏ وَقَالَ إِسْحَاقُ بْنُ رَاشِدٍ عَنِ الزُّهْرِيِّ عَنْ عُرْوَةَ وَعَمْرَةَ‏.‏
USC-MSA web (English) reference : Vol. 6, Book 60, Hadith 414
Arabic reference : Book 65, Hadith 4891