Nafi' said
When Ibn 'Umar was asked about person who had given three divorces, he said, "Would that you gave one or two divorces, for the Prophet (ﷺ) ordered me to do so. If you give three divorces then she cannot be lawful for you until she has married another husband (and is divorced by him)."
Narrated `Aisha
A man divorced his wife and she married another man who proved to be impotent and divorced her. She could not get her satisfaction from him, and after a while he divorced her. Then she came to the Prophet and said, "O Allah's Messenger (ﷺ)! My first husband divorced me and then I married another man who entered upon me to consummate his marriage but he proved to be impotent and did not approach me except once during which he benefited nothing from me. Can I remarry my first husband in this case?" Allah's Messenger (ﷺ) said, "It is unlawful to marry your first husband till the other husband consummates his marriage with you."