(the wife of the Prophet) When believing women came to the Prophet ﷺ as emigrants, he used to test them in accordance with the order of Allah. 'O you who believe! When believing women come to you as emigrants, examine them . . .' (60.10) So if anyone of those believing women accepted the above mentioned conditions, she accepted the conditions of faith. When they agreed on those conditions and confessed that with their tongues, Messenger of Allah ﷺ would say to them, "Go, I have accepted your oath of allegiance (for Islam). By Allah, and hand of Messenger of Allah ﷺ never touched the hand of any woman, but he only used to take their pledge of allegiance orally. By Allah, Messenger of Allah ﷺ did not take the pledge of allegiance of the women except in accordance with what Allah had ordered him. When he accepted their pledge of allegiance he would say to them, "I have accepted your oath of allegiance." (Using translation from Bukhārī 5288)   

أَنَّ عَائِشَةَ زَوْجَ النَّبِيِّ ﷺ قَالَتْ كَانَ الْمُؤْمِنَاتُ إِذَا هَاجَرْنَ إِلَى رَسُولِ اللهِ ﷺ يُمْتَحَنَّ بِقَوْلِ اللهِ تَعَالَى {يَا أَيُّهَا النَّبِيُّ إِذَا جَاءَكَ الْمُؤْمِنَاتُ} [الممتحنة 12] الْآيَةَ قَالَتْ عَائِشَةُ «فَمَنْ أَقَرَّ بِهَذَا مِنَ الْمُؤْمِنَاتِ فَقَدْ أَقَرَّ بِالْمِحْنَةِ» فَكَانَ رَسُولُ اللهِ ﷺ إِذَا أَقْرَرْنَ بِذَلِكَ مِنْ قَوْلِهِنَّ قَالَ لَهُنَّ رَسُولُ اللهِ ﷺ «انْطَلِقْنَ فَقَدْ بَايَعْتُكُنَّ» وَلَا وَاللهِ مَا مَسَّ رَسُولُ اللهِ ﷺ امْرَأَةً قَطُّ غَيْرَ أَنَّهُ يُبَايِعُهُنَّ بِالْكَلَامِ قَالَتْ عَائِشَةُ وَاللهِ مَا أَخَذَ رَسُولُ اللهِ ﷺ عَلَى النِّسَاءِ قَطُّ إِلَّا بِمَا أَمَرَهُ اللهُ بِهِ وَكَانَ يَقُولُ لَهُنَّ إِذَا أَخَذَ عَلَيْهِنَّ «قَدْ بَايَعْتُكُنَّ كَلَامًا»