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."

Sahih al-Bukhari Book 65, Hadith 411